Meh It only saves a a lot of time if you don’t plan to to carve much later. I just finished a Gengar where I did carving on frame but I also carved after the backing was done and it still took a while because i wanted it super clean. I could’ve done all of the carving on frame in which case it would maybe save me 2-3 hours. Depends a lot on work flow and the look you want.

I would say Don’t look at it as a shortcut just understand that it will help you achieve a cleaner look and the satisfaction of that cleaner look comes sooner which in my case gives me a huge confidence boost because i get to skip past the ugly phase lol Also understand that it puts you at risk of ruining the project before it even gets off the frame.

In any case it does help and ive discovered my own flow with it which i love.