I've been working on getting the script to simplify the mask, meaning you can use a ton of anchor points cutting out the mask without having to move all those points in the next step. The mask you work with when expanding will be a simplified version. Simplifying bezier mask paths isn't exactly easy - it is it's own fancy script 300 lines long.
So what's taking so long if that parts done? The current J&G script relies a ton of comparing two masks... now there's a third. So practically every section of code has to be adjusted and now take into account the 3 masks. Certain sections (SmearPoints, cough cough) are not cooperating and taking forever.
I hope to have it done by the end of the week so I can start on other things.
Update (7/22): Major progress has been made on the script. I'm going to be testing this one pretty heavily to try and find all the errors this time before pushing it out. So far, it's looking good. The simplify mask option is really helpful and caused significant overhaul of the comparison code, so I hope it will work out. There's a couple other goodies I added that will get added to the patch notes.