I use one expression pedal for both volume and wah with my Stage. I assign one of the FX switches i to iv to switch the wah ON/OFF which maintains the current volume level.
I have a couple of Performances set up like this for songs that need wah. For other Performances the FX switch get used for whatever is needed.
I’m assuming you use a remote foot controller?
A Boss FS6 dual footswitch may help. It has a battery to power just the switch leds. You can set momentary or latched actions per switch and an led illuminates when a switch is operated.
In latch mode, it tells you the switch is ON when pressed and you’ll surely hear the FX working?
I’m using EMG SAs on my Strats, sound wonderful, no problems with my Stage. 👍
I use OnSong and have used Songbook Pro to manage set lists. Both can send midi commands into Kemper on song selection to load performances etc.
SongBook Pro only sends one midi command but OnSong allows sequential midi commands and is more flexible for me.
I use a Stage with a Yamaha Bluetooth midi adapter and an iPad. Works perfectly. 🙂
I have a Stage (around 2 years old) and Performance #1 button was misbehaving badly. I saw this post about Spy Mode and searched it and discovered that you just hold the INPUT and BACK buttons down at the same time to enable/disable Spy Mode.
In my case, I found that button #1 was registering about 5 out of 10 pushes with a finger. The 5 fails were all together in a block. Like it works a few times then dies a few times. Although it sounded like the switch below was clicking on/off, the LEDs and function did not respond. I tried cycling the switch a few hundred times but no real change.
I used a cocktail stick to add a tiny amount of silicon lubricant to the barrel of the metal button, then rotated/pushed it repeatedly to distribute the lubricant. Hey Presto the button does not fail anymore! 
I've now similarly lubricated all the buttons and they all feel really smooth and reliable.
I understand why the button travel should feel better but not why the switch functionality improves. 
I also use a Voice Live 3 and like other vocal processors it has a guitar pass thru socket, so you just plug into the vocal processor first, then thru to the Kemper.
You could simply make a small adapter TRS plug to TRS socket and wire it T to R, R to T, S to S (swap over T & R)
TRS polarity adapters are available commercially. Have a search on Amazon, they’re not expensive.
I’m still using a Shure GLX-D system with a Kemper Stage. Never had any problems and works perfectly with active pickups in both electrics and acoustics.
Not all cheaper wireless products work well with active pickups if at all.
Good point Burkhard, thanks!
i don´t think so, but isn´t it always loading the last performance you used?
Yes it does, but at the end of a gig the active performance is typically not what a gig will start with.
It would be useful to be able set any performance as the default boot up mode.
Is it possible to set a specific Performance bank to load on startup? For example bank 20, slot1.
I use the EXP pedal set to volume at the output. This allows global volume control, typically between a working level and zero, so I can regulate my overall volume on the fly.
For rhythm/lead level adjustments, I set this up in performance mode on specific rigs when required, either as a level morph on the current slot or a separate performance slot set up with delay, harmonizer, etc. as the lead passage needs.
Hope this helps.
Ah! had a feeling that may be the case. I guess I need to improve my stomp action!
Thanks Ruefus! 👍
I have two FX assigned to switch III so I can toggle between them.
If I tap the switch, the toggle works most of the time but occasionally it fails to change.
If I hold the switch down a bit to ensure the toggle happens, when I release it the FX toggles back. 🙁
Is it possible to turn off the long press function per rig or globally?
I’ve been using a Shure GLXD4 wireless system for some years, gigging with a couple of Strats fitted with EMG SA active pickups, and an SG.
This system works perfectly with everything, including my Kemper Stage.
It also works perfectly with a couple of acoustics, one with a Lloyd Baggs pickup, the other with a Headway pickup, both under saddle powered piezo type.
Some of the guys in the bands I play with have tried using various different cheaper wireless options, but experienced problems with drop-outs and noise pickup, plus battery life issues.
Some products just refuse to work with active pickups.
I’ve had absolutely none of this with the Shure system.
The rechargeable battery from the body pack fits into the receiver for charging and it lasts for 16 hours. There is a current charge display on the receiver so you always know where you are working.
I’m dreading it breaking down, I don’t know what I could replace it with that comes close. 😐
I guess, this cannot just be a misadjustment. If the pot would generally not reach its maximum, the calibration with the PROFILER would adapt to it.
Good to know, thanks Burkhard. 👍
This may be a mechanical issue. I’m not familiar with the internals of the Mission EP1 but a lot of Wah and Volume pedals have a rack/pinion gear or belt drive mechanism to the control pot. I’ve had similar pedal situations where the pot doesn’t travel all the way to the end as it should.
A possible fix is to open the pedal and loosen the drive mechanism until you can rotate the control pot by hand to the desired position, then retighten the mechanism adjusting it to the desired operating “feel”.
Hope this helps!
Ah OK, I misunderstood. Thanks for the info.
Edit: Email with backup file sent to Support.
Hi Burkhard, I'm using "off" and "at heel" to mean the same thing - no volume - no sound. Sorry for any confusion.
You may have nailed it.
I always have the WAH function on a stomp switch and set to "bypass on stop", so the pedal is basically always a volume pedal until it is told to be something else. I never have a slot with WAH enabled on selection.
When WAH is activated the current volume is maintained of course, when deactivated, the current volume is also maintained (the pedal will be positioned wherever it stops being used), so the volume doesn't usually need to be altered further. I tend to rock the pedal down to heel between songs - e.g. "off" with respect to volume.
I haven't noticed any other issues doing this, it seems to work really well.
I have considered using a second pedal for dedicated volume but this will mean a pedalboard upgrade for a wider model. 
Thanks for the explanation on WahPedal>Volume behaviour, it does sound like that is probably the issue.
On another note:
I did take a RM backup but I can't find how to submit it to Support. The Contact web page doesn't appear to have any upload method.
What is the usual procedure here? Thanks.
ST, thanks for the advice. I checked all the slots and they all have the Volume set to "location - output" and range "-5".
I tried it with the volume lock both on and off, nothing changed unfortunately. 
I use it as a final output level and tend to turn the volume down to "off" between songs.
Burkhard, it's a Dunlop volume X expression pedal set Wah>Volume but I also tried it as a dedicated Volume pedal in socket 1 but it's the same result. This not really a performance issue as the volume pedal is always ON somewhere when playing.
I discovered this by accident in rehearsal. I had the volume turned off (at heel) and I was reviewing the stomp switch assignments, so I was selecting each performance slot 1-5 in turn and looking at the screen info. When I selected slot 2, I heard some string noise from the guitar I was holding and realised that that slot was still passing some signal .
Further investigation showed I had a few slots in different performances, that did the same thing.
What I also found is that once a slot triggers the issue, all the other slots in that performance then pass low signal as well. It's as if slot 2 is tweaking the general level up a few dB even though the pedal is physically at heel.
I'll look into doing a backup as you suggest and raise a ticket.
