Problems with DullCoat or Gloss Coat?

Eric,
I've not yet had any problems with yellowing of Dullcote or Glosscote, but on most occasions the full thickness of Glosscote never seemed to dry completely - even after several weeks when I rubbed a finger along a 1/144 scale airliner covered with the stuff, I could feel the "drag" of paint not fully cured.
Now I always use Future for glossing models for decalling and for final gloss coats - there's never any yellowing with Future, and best of all, it dries hard. It's a helluva lot cheaper than Glosscote as well.
Cheers,
LeeTree

Possible to use your coats on a test piece ( old wings are good ) and apply over various colors - include white, and a little time will tell.
I use a gloss coat over matt paint to apply the decals and either leave it there or matt or satin to seal and finish, although this can build up layers a bit - probably old school, but for WW II schemes works well.

I have never had a problem with dull coat turning yellow, but gloss coat will after several years. I have had very good results with future, and so far have not had anything turn yellow on me.