If it ever came down to it, having the battery in a battery holder that is meant so that it can be easily replaced would negate their definition of "non user serviceable" in a court of law... They probably need to rethink this whole stance
Also, using standard TORX and Phillips screws as opposed to tamper proof versions would not do well for their claims there...
I used to design medical devices as well and those had to use fasteners that the average person didn't have around or could get their hands on easily.
Yeah, it's things like this that drive us all nuts. I'm happy you posted your resolution and that you did the work, and solved the issue. It helped me decide to do the same and see what happened with my unit. To me, it's like owning a car that starts behaving oddly or making a noise. What's the first thing we do? Open the hood to look around! LOL Sometimes it's an obvious issue we can fix at home, sometimes it needs to go to the dealer. Everyone will have their thoughts around this whole debacle, but at the end of the day, if it's fixed and we know that it's one of two possible causes or both in conjunction, a lot of people will be happier Kemper users. We can get back to making music with the thing, instead of getting annoyed every time we power it up!