Agree the newer coils aren't as critical - but I know the older ones were. They (Dometic) told us they like/recommended 1/2 a bubble in either direction.
Honestly though, that was late 80's early 90's. I don't know when they changed them to the newer design. I would also wonder about replacement cooling units - new or old design? FWIW....
1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake