What would probably be feasible would be to have a plug-in in the future that would let you select a fillet face and then it would replace it with a modified "bead" version.

Having specialized stuff like that in an optional plug-in command rather than baked as an option directly into a standard command like Fillet tends to help keep the regular stuff working more easily.

That would probably need a plug-in that would have some compiled C++ code for hitting the surface data at a lower level and not really a script one though. I don't have a system set up yet for doing C++ plugins.

- Michael