New version with some fixes 
I'd say this is pretty close to the stable release. I haven't encountered any major issues on my machine so far.
New version! Wrapping up browser support. If no bugs are found in this version before @Andreas_Hegenberg releases the new stable BTT, then I think this is going to be the stable version. It's definitely RC1 material 
EDIT: Oh man I fixed the Now Playing output bug! Now iTunes widgets can display songs even if they have double quotes in them. Updated version to 2.563-4, haha.
If anyone's wondering, I used this code to escape the double quotes:
set aString to trackInfo
set astid to AppleScript's text item delimiters
set AppleScript's text item delimiters to quote
set aString to text items of aString
set AppleScript's text item delimiters to "\\" & quote
set aString to aString as text
set AppleScript's text item delimiters to astid
set trackInfo to aString
)New version! Is this version the "Snow Leopard" of GC-BTT? 
In seriousness, I think I've got performance to an acceptable level. I'm now seeing some of the lowest energy usage from the preset in a long time on my system. Things also just feel much, much snappier as a result.
EDIT: After a few hours monitoring BTT, I'm really happy with the performance of this version. Honestly, if I wasn't the one who made the changes, I would've guessed that I increased the refresh rate of the scripts because of the sheer performance boost.
Please report on how performance of this version is on your machine so I can make final adjustments! Thanks everyone 
New version with Spotify long-press widget! It's a little bit more basic than the iTunes one, but I did leave a bunch of placeholders in the widget for whenever I or someone else is able to get those additional functions working. For now we've got shuffle/repeat and copy track link 
enjoy @ZucchiniZe
New version! @Andreas_Hegenberg this version is very, very stable. What version of BTT do you think is going to be the next stable release?
@Randy_Saeks after testing, I can't reproduce your calendar bug. Have you changed it at all?
New version again! Since I had some extra time, I made the volume up button display a dynamic icon it doesn't require any extra scripts since it returns the alternate icons as text in base64. This'll probably be the last update for today, haha.
@TheAnonymous010 that's great news!!
EDIT: Fixed a small bug with the repeat button using my newfound widget updating powers 
decided to just replace the current version rather than releasing a new one so soon.
Okay, I lied, I've got one more tiny new version. Couldn't help myself
New version! @Harrumph had an idea that was so good how could I not put out a release at 4am?!
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!
