Hi blackboard,

I've posted an updated version with a few improvements http://moi3d.com/forum/index.php?webtag=MOI&msg=11063.1

1. adds to existing selection
2. compatible with a wide variety of faces
3. can be run in the middle of the Fillet command without cancelling Fillet
4. selection is undoable when using v5

Re:
> Maybe you can add this function?select all edge chain by one button?

There are already commands that do tangent propagation http://moi3d.com/forum/lmessages.php?webtag=MOI&msg=8665.195

Also, ACIS in v5 does some automatic tangent propagation http://moi3d.com/forum/index.php?webtag=MOI&msg=11043.4

- Peer