I am not sure if this counts as request or bug as it's "correctness" is debatable, so, going with request for now:
When fully capitalizing a word by marking it and pressing shift, the letter ß gets replaced by "SS" in words like, for example, "Spaß". This was the usual way to do it in German for a long time and thus isn't "wrong".
But since 2017 the corresponding capital letter ẞ is officially part of German orthography (and it's also is present on HeliBoard)
Describe the solution you'd like
It would be nice to either change the behavior or at least have it as an option so that ß is shifted to ẞ when using the capitalizing feature.
Describe alternatives you've considered (if any)
Alternatives are either being okay with "SS" or typing the ẞ manually.
Both doable, it's not high-priority, but would be a nice-to-have.
App version
HeliBoard 3.7 (F-Droid)
German (Germany) layout with English (USA) as secondary language
Google Pixel 7
Android version: 16
SDK level: 36