I'm not sure what you trying to do with Future, but this is how I use it.....and I use it on every model I make regardless if it will end up having a gloss or flat finish.
Canopies: I dip canopes in FUTURE and let it drip off to one edge. It dries pretty fast ( like 30 mins) and it will give the canopy a very clear look.
For the model: I paint the model and make it as clean looking as possible. Then I spray maybe 2 coats of FUTURE on all surfaces ( not canopy though) and let it dry. the reason is to give a clear surface for the decals. Apply the decals after the FUTURE has dried, then spray FUTURE again over the decals. This will pretty much hide all the clear areas of the decals that you dont want showing.
After this, you can weather the model with oil based paints. Oil based or enamel paints will not damage the FUTURE which is acyrilic based, so if you want to remove some of the weathering, you can do so without ruining your paintjob.
After you get the model how painted how you like it, apply a flat coat or whatever dull/flat/ gloss finish you want . For aircraft, I use dull or flat finishes.