Awesome. I've just uploaded GC-BTT 2.600, and I took the liberty of taking some newer screenshots for you to include in the release notes since it's changed visually from 2.536 quite a bit.
Improved UI:
Expanded widgets on long-press:
Emoji and browser tabs:
New modifier key menus:
New experimental version! This one is actually experimental, so expect new features to be work in progress. Don't run experimental versions from now on unless I specifically mention a particular one is stable, or unless you're willing to sacrifice battery life to try new features that may or may not work properly. etc etc 
New experimental version with collapsable menu bar on the main screen! @Andreas_Hegenberg what's the timeline on the Reuse Widget functionality?
Please let me know what you think of the collapsing functionality! In particular I'm wondering if the tap target for the chevron is too small.
New experimental version! Decided screw waiting I want cool features now.
That is weird. Well, in this new version I moved the location of the toggle scripts, so it should work this time! Hopefully
New experimental version! Quite a few changes in this one.
New experimental version - the menu bar update 
I recommend disabling the "Animate Group Open & Close" global Touch Bar setting for the best effect in this version. @Andreas_Hegenberg can there PLEASE be a setting inside each button group's preferences to force animating/not animating on group open?
The only thing left is dock settings, I think, so that will be next.
New experimental version! Dock settings + GC-BTT Config Presets!
New version! The holy-crap-presets-work update
I made a new version that makes it a bit easier to decipher how to add your own preset 
I also got the language picker done (finally)!
New version!
New version!
I actually prefer the lighter buttons myself. In an unreleased version I had set all the buttons to the system default, but I thought they were too dark and didn't provide the amount of contrast I wanted between the scrollable container and the menu bar.
In any case - new version! 
Thank you everyone for your feedback about the combo button! I really want to keep improving this particular key, so please let me know what you think of this new one and what you would change.
New version! @PhilMac try this one out and see if it works for you. I'm not sure what's causing your issue but maybe reimporting will do the trick.
New version!
This took a while to debug. Turns out you have to wrap these get_string_variable statements in tell statements, otherwise they won't work. Here's the full code for the Play/Pause button:
tell application "BetterTouchTool"
try
set showMediaControls to get_string_variable "BTTCurrentlyPlayingApp"
set playerState to get_number_variable "BTTCurrentlyPlaying"
end try
end tell
if showMediaControls is not "" then
if playerState is 1.0 then
return "Pause"
else
return "Play"
end if
else
return ""
end if
And the rest of the buttons:
tell application "BetterTouchTool"
try
set showMediaControls to get_string_variable "BTTCurrentlyPlayingApp"
end try
end tell
if showMediaControls is not "" then
return " "
else
return ""
end if
Much simpler, super performant, and has identical behavior to the Now Playing widget.
Alright, I think it's ready for the first test run. This is a hefty update to settings!
New version!
New version! No screenshots for this one, but a lot of under-the-hood changes that make the behavior of the dynamic buttons a lot less janky and unpredictable. Please test out these new dynamic button settings! Especially from a fresh setup, I need to see if they initialize properly.
Tiny new version - please test and see if there are still issues with the date not being properly initialized.
@Sahaj.Patel making upgrading easier is what these latest experimental releases are all about 
Small new version once again! Now that I know things are working properly, some tidying up 
