Frankly I have never been able to understand why anyone has problems applying Future or its clones - just brush it on, use a tissue to soak up any pooling and that's it.
Use one coat, don't go for two because you only need to apply the second with a brush where decals are going. You lay the decals in the wet Future and let dry - it is the best decal settler I have ever used. No need for anything else - I have used it for all types of decals from the best modern types right through to ancient Frog ones with no problems.
Personally I just think that some modellers are afraid to experiment.