Welcome to the forum @JanRoza
Single click should work fine. At one point on the way to 2.1, one had to use right-click Open.
That’s still supported (along with the other right-click menu options), but seems like hard way.
and I don’t know if it’s possible to have a double-click requirement in the new implementation.
When I say new I mean completely rewritten to use the Avalonia UI framework to replace old.