What is still missing when using Ctrl+P and Ctrl+Shift+P?

In version 19.1 one can show/hide merged commits if "Follow only first parent" is selected.

If you need more worktree commands than in 18.2 available, please request them separately.

Who would volunteer to co-operate with us on a long-term base to maintain the language of their choice (except of German and English)?

Chinese

German