Access extended popup characters by tapping

I am using AnySoftKeyboard for a while now and one feature I really like and am used to is to access extended popup characters (actually only the first one) by double tapping. I cannot find if this behaviour is controlled by some setting, so it seems that it is built into the Latvian keyboard (maybe in other layouts as well, but I am using this one) as additional characters for a letter can be accessed both by long pressing and double tapping.
Additionaly, if a letter has more than one extended character then it could be accessed by more taps:

- first extended character - double tap;
- second extended character - triple tap;
- and so on.

Coud it be possible and reasonable to implement this in FlorisBoard?

The issue names no files, tests, or entry points. Begin by locating FlorisBoard's handling for popup characters and tap or long-press gestures, then compare the Latvian layout's extended characters with the requested double-, triple-, and further-tap behavior. Done means the documented tap sequence works for letters with one or more extended characters without breaking existing long-press access.

Written by the indexing model from the issue text.