+10 From us too, doing anything more than a few extensions is killer or you do templates and those change with each release. I know with as many phones as you support things like pictures are hard, but anything specifically with master templates for BLF is much appreciated.
If I have a recommendation it would be to design a framework that allows the manufacturers or others like us to do the leg work for things like pictures and notation of where the sidecar extensions start, etc.
I would expect an "exchange" of sorts where we can see the work of others with the ability to rate and the like would be straightforward for even the community to help build.
Love the current progress with settings within 3cx, this is one of the weakest parts of 3cx and it is great to see progress.
Keep it up.