Hi Mala,

re:
> Is it possible that deforming of a spline is not possible anymore after booling or connecting geometry together?

Yes, that's correct that there is a limitation to the history update mechanism where
editing curves will recalculate surfaces generated from them. The history updating
mechanism will not persist through some kinds of operations like booleans or trims.

That is something I would like to improve in the future but it will take a lot of work to make
a deeper history function that persists across those kinds of modifications.

- Michael