I'm completing a newer Spitty release and used the included Tamiya decals. I found them to be on the thick side and some refusing to conform to certain angles like the yellow leading wing stripes that had to be masked and sprayed. I had to use tons of Solvaset decal solution which is very strong and melts the decals down as if they were painted on.
Even though the decals eventually settled down and look ok, I think next time I will go with aftermarket ones and suggest the same in your case.