Apply "Round corners" Filter to all glyphs

the filter “Round corners” only works on selected paths.

Is there a way to apply the filter to all selected glyphs in all masters?
Is it possible to apply the filter to the background too?

Version 2.3 (895)
THX! Georg

When you run it in Font view, it ignores the path selection:

Still, it will only work on what you see, so you have to switch through all masters. And repeatedly apply the filter.

It works with Helvetica but it doesn’t work with the font I am working on …
Mine is a hand-drawn, may this be the reason?

May I send you the .otf?

Does the font have many nodes? Than the problem will be that filter cannot apply rounding because the segments are too short between points.

the glyphs do have many nodes, yes.

The filter works on selected paths.
The filter does not work on selected glyphs.

Can you send me the .glyphs file please to support (at) (this website without www). I will have a look.