Hi Marco,

> I've experimented that it doesn't seem to be any relationship between
> "ShrinkTrimmedSrf" and "merge" commands.

Yes that's true, they work on different types of sub-objects - ShrinkTrimmedSrf will only change the "underlying surface" of faces and does not make any modifications to edges, while Merge only does modifications to edges (currently - I'd like to also have some way to merge 2 adjacent surfaces as well but I have some hope to add merging functionality into join rather than keeping them as separate commands).

- Michael