Scriptnode fade then softbypass

[whoopsydoodle]

I'm trying to design a scriptnode that will switch between a series of different FX nodes. I'm using softbypass to turn them on and off to save CPU. However I would like to switch between them as seamlessly as possible so I'm trying to design a script that when switching will enable the target path, then fade to it, then once the new path is the only thing passing signal it should softbypass the old path.

I'm wondering if anyone has done this before and can point me in a good direction? There doesn't seem to be any premade nodes designed for this I will have to build something probably using multiple switcher nodes with one lagged behind with a smoothed parameter node? At least, that's my first idea for making this work.