The Kemper can already import IRs for use as cabinets.
However, I do see another use for IR in guitar. You can also change the tone of your guitar. If e.g. you have an acoustic guitar with a Piezo Pickup, there are IRs which allow you to transfer the sound into miced famous acoustic guitars. This works quite good!
Why not have the possibility to put one IR stomp (most probably on A)?
The problem with an external device is, I can not switch it with the profiles, it remains always an additional step.