BAM 200 is not done for giving a Flat response nor done for guitarists at the base but it was quickly a solution cause ; a classe D, 4 ohms accepted for 200 watts and not expensive (plus the powerKabinet didn't exist at that time).
vtgearhead took measurements and gave the settings to have the flattest response (thanks to him
), it is here : RE: Poweramp for Kemper and Kabinet.
The reason why i choosed this device with all these datas
I totally get that the BAM200 was originally marketed towards bassists, but apparently it's found a home among guitarists (some jazz guys actually plug straight in and use it as an alternative to a polytone). The EQ is flexible enough to support guitar, as you noted, so all good. As I mentioned, you can certainly find tones that are hollow/odd sounding, so it takes a bit of EQ tweaking to find your sweet spot, but I use this with a Kone, and think it sounds pretty darn good (again, not quite as good as the internal IcePower module in my Toaster, but certainly close).