Can FP units be used to level main units more efficiently?

A thought occurred to me and I have yet to test it out: if you take a FP unit to max level, and then fuse it into another unit, will it reward more experience than what you invested into the FP unit to max it?  In other words, is it actually possible to gain some experience efficiency by using FP units?

For example, if I just let a FP unit tag along on exploration runs until maxed, and then fuse it into a main unit I am trying to level, will that main unit get more out of the fusion than it would have if I had just ran the exploration without the FP unit and let the main unit soak up the extra experience, and then fuse in the unleveled FP unit?

Anyone feel like doing some math?