I've now used this on Liberator (the Eagle sculpt on the frame) and my latest build (the slide) and I'm convinced it can help where tape is almost impossible fine tune.

Pebeo Easy Peel Liquid Latex Masking Fluid - https://a.co/d/7zJcq8o. It's temperamental when it comes to curing but it seemed to be ok with a quick 5 minute flash cure. Any longer than that and it could still be removed but it was far mor difficult. I'll be using it on the current frame and will keep you guys posted.
JettaMan OUT!
It is something I need to try out. I am all ways finding places that is hard to mask off.
That's cool. I've seen some model builders use something like that.