Tweak Relax improvement request

[Fonte Boa]

This is a request to improve Tweak Relax, or maybe Vert|Tighten.
What is the gain? Keeping geometry volume after those operations.
I've found a exactly similar took: a Marius Silaghi plugin for 3ds max.

[Justanother1]

Now hold on, I use tweak relax a lot, and I like it ..... However, on a different note, would it be possible to work in some kind of "Mask" feature .... as to lock certain elements in place and have them not affected by tweak and sculpt ... yes I know it's possible as objects ... but what about polygons? ... maybe using Groups or something

[Fonte Boa]

Jusanother1,
have you already tried to use Tools | Magnet Mask?