Actually a lot of modelers (including those outide of rocketry) use Future as *base* for decals, because it of its ablility to reduce decal "silvering" that can often occur with decals applied on top of matte paint. This was actually one of its first uses in the modeling world.
Of course, a good clear coat of Future on top is always nice.
I've used future over blushed paint. it takes 3-4 coats with atleast a day to dry betwen applications to bring a shine back
not the best results but. much better than the spotty blushed look. I would like to find some of the finess-it, micro suggests
I've read on model forums where some people dip the decal itself in future, but there is no moving it around once on the model.so I won't be trying that.