Don't think I like that decal system.
After seeing your experiences with them, I'll avoid getting some for a 1/32nd scale P-51D-5, and choose a different colour scheme !
The Eduard "system" reminds me of some decals I used many years ago, on a RAF Phantom, from a UK source, now defunct.
Can't remember the name offhand, but I still have some, and they were a "dry transfer" system. The decal was placed loosely in position, with a "low-tack" backing allowing precise positioning. Once satisfied on the positioning, the decal was then pressed down, and water applied over the thin carrier film on top of the decal, which was then easily removed, leaving a perfect image with a "painted on" look and no carrier film edges, especially effective on a "metal" finish, where a carrier film can nearly always be seen on, for example, lettering blocks.
Possibly the best decals I've ever used in over 60 years of modelling.