[Suggestion] Possibility of non-destructive workflow ?

[meutzitzu]

Can any of these tools be used via the modifier stack, by any chance ?
I'd really like to be able to fillet and boolean with curves

[Lichtso]

I would like that too.
However, I don't think one can add modifiers via the add-on API.
Instead it would require a fork of Blender to change the core code-base directly.