New features in custom toolbar tabs

This is actually possible right now if you directly edit the JSON files of your custom ribbon tabs, it just isn’t yet possible within the UI.

Refer to these posts for a guide on editing the JSON & examples of custom tabs that include the movement/rotation increment components:

You can also right click a built-in tab like the Model tab and duplicate it, which then allows you to edit the contents of the new duplicated tab and retain the increment components.