They will eat a little, but as soon as you put in lmb they'll be gone. I'd suggest feeding if you can, it makes a nice difference. Again you can't overstock the FH.. I put over 20 lbs into my .2ac pond to start.. they're just so easy to eat up once you get the bass in there.
Don't be afraid to go higher on the ratio of BG to LMB, especially since you want to put the lmb in next spring. I'd go with various sizes too, maybe even some 4-6+ inches.