Hi Petr, it works great!

I think that's a nice idea to have it work by following the "example" of the initial single selection, kind of like the priming mechanism for edge or face sub-object selection with window select or select all.

I'd like to add something like this to the regular selection palette for V2, in addition to selection filters. I was previously thinking of having some kind of a menu that popped up a bunch of things like "Select all curves", "select all surfaces", "select all points", etc... But your way shows a good way to potentially combine all those into one thing.

Hmmm, one potential problem though - say you have just the box selected, and now you want to select all curves in addition to that. It won't work for that since it will take the box as the example right away... Probably not a problem for your use but it may interfere with using it as a totally general replacement for separate menu items...

- Michael