rvp I'm not so certain that this is needed.
Me neither, but fixing unrelated problems in the move isn't a bad thing whatever 🙂
I tried with two different keyboards (one Microsoft, one Logitech), same problem. I also tried setting -model to what I actually have instead of generic pc105 but that doesn't make a difference either.
Maybe it's a bug affecting only a few keyboard layouts.
Could you please try the following: run
setxkbmap ch, then (in a text field somewhere inside a Qt program) press the key which is to the immediate left of Backspace (it's the "=" key on US keyboards), then press the E key. You should get "ê". If you get "e", you have the same bug than me.
I'm going to build @pin's new LXQt packages right now and see if that solves the problem.