What you’re describing are what we call “sticky” settings.
Let’s drill down a bit.
Non-sticky settings revert to defaults every time the command is used.
Session sticky settings remember the last used setting within that Rhino session. When you close and restart Rhino, the settings revert back to defaults.
Permanent sticky settings are saved on exit and restored when Rhino is restarted.
I don’t know what Curve piping is supposed to do.
It sounds like they are “non-sticky”.
My guess is resetting them to defaults when closing and restarting Rhino might be best.
What do you and others think?