I can tell you are trying to maximize carry capacity in your small pond and that you have taken precautions to ensure minimum required water quality both with 24/7 and sequestration of phosphorous. I would agree that this would help to keep your water happy for the fish.

I very much like esshup's rec for adding the LMB, both for the recommended size and the quantity. Were it me, I would follow that advice to the letter and do this as soon as I could. You mentioned stocking 700 HBG. I wasn't certain if you meant 700/acre or 700 in a 1/5 acre BOW. But if the latter, that is a very high population density for a trophy pond. They could already be very near the biomass that the feed can support which would mean that growth will slow unless some are removed. How much you are feeding is an open question. I understand 5 secs a day but that doesn't state the daily weight of feed. Can you tell us what weight of feed has already been fed (eg how many bags)? Also would be great if you could test feed delivery rate in lbs/sec.

The lower two fish don't look any different to me than GSF. They don't look like Fx I see commonly around here either. Pretty good chance, as esshup suggested, that GSF made it into the pond with the GAMs in high water. Were it me, I would remove any I caught. I think also, if I were to allow recruits to grow out, I would try to select those recruits that resemble the original F1s the most.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers