If you don't want BG you will need other forage. Some combination of tilapia , FH , TShad , GShiners , craws and /or feeding. I would put in some RES for snail control. Stock the main pond with all the predators and forage just as normally done but under stock the LMB numbers by 20-30%. Close off the forage pond first.

On the small forage pond the idea is a continuum. First with no predators grow the extra forage by feeding and then force them into the main pond so that the forage pond is almost empty. Then close it off , shock up some adult forage fish (or catch them by line or seine) and put them back in the forage pond to re-seed it. Then 8-12 mths after original stocker LMB spawn in the big pond, and you do a shock survey (or by seine or line) keep a few of the 12in LMB (biggest best conditioned females) exhibiting the best genetics and put them (say 25 fish) in with the forage which will be growing in the forage pond. Those few LMB will be hand picked and have the best chance of superior growth (all they can eat with no competition) with no chance of being eaten by their parents. They will not be able to eat the adult forage tilapia but will eat FH and small tilapia/other forage. Those 25 LMB will not make a large difference in the amount of forage grown in the forage pond. After a year run all those LMB and forage out of the forage pond and start the process over. A never ending supply of the best of the brood 3-4 lb 2 yr old LMB and forage going into the big pond every year. Those extra 25 4lb LMB will help keep down the small LMB in the big pond and replace the first year class (and each succeeding year class) of LMB which you harvest/or die (natural morts). In short you will always have extra forage and some hand selected female LMB in the range size that is usually missing in LMB ponds due to many range bound 10-12 in LMB.

By emptying the forage pond you will remove the numerous adult fish which can produce the breeding suppression chemical (factor) in ponds which are near capacity with fish. Tilapia , GShad , BG and others have been proven to suppress spawning/reproduction in themselves and other fish when there are lots of them or near carrying capacity.

That is the concept. It will take some work but any good LMB pond does.