We hardly had time to work on 3.7, there have so much going on. As explained before in a different topic, it is hard to keep track of bugs on the forums because there are so many discussions going on. Please report it by email or a support ticket.

Depends on where you live. I would look for some rolling desk solution. You can buy them at Amazon for example.

Your first step would be to put a print in your function and see if it really triggers the function when you press the button. Then you know that it is not hardware related.

Tony, are you using a new Knobster or an old one?

You can change it if it is out of full screen mode. Make sure the lock is unlocked and drag your panel a bit.

Make sure that the Knobster is selected for your panel. Have a look at this instruction video.

https://blog.1000bulbs.com/home/led-drivers-constant-voltage-vs-constant-current This is what I was referring to. The result of a constant current driver is usually much more linear. They are made for this job and generally give a very stable result. But for just a few LEDs it might be a bit overkill.

We don't use it to keep track of bugs, because it gets lost between all the other comments. It's better to report it by email or a support ticket.

There's a new version since July.
RPi 4 image comes this month I think. The problem is that it might have to be a separate image for the 4, but rather not...

It works with the RPi, but indeed not with tablets due to the USB 'problem'.