Some of that .25" daily vertical water loss is due to evaporation, so I'm very glad the polymer treatment was successful - that's an amazing turnaround!
Have a good vacation - we will be here when you return to help assess this situation. I don't have any experience raising fish in the broiling South, hopefully some of our seasoned Southern brothers will chime in with their experiences. I'm grateful you aren't losing 5# LMB - BG are cheap and easily replaced worst case scenario.
Might be worth calling American Sportfish - Lusk recently merged with them and Shawn uses a lot of polymer sealing client ponds. I'm sure they would have some practical experienced feedback. I also recommend sourcing fish through them moving forward.