How is the pondweed situation? The greatest threat the feed presents are the additional nutrients that will grow many times their weight in plants. 100 lbs of feed will easily nourish 800 lbs of FA, Elodea, etc. We are fast approaching the most dangerous time of year for fish. As daylight hours rapidly diminish, the period of night time respiration is rapidly increasing. But in late summer the effect is compounded by warm water temperature. Its a fine line between water that supports trout year round and water that can't. Too much primary production is worthy of your concern, especially considering that you keep trout year round.
Luckily, plants have gone down significantly and are not an issue like they have been before. However, I think all the decaying plant matter at the bottom can't help. The super hot weather seems to be over and surface temps are back down to 24C (75F) and should continue to drop. You are definitely right about my pond being on the line between a year round trout pond and a seasonal one. The nest couple of weeks should be a good test, and then it should be okay as September comes and temps start to drop, especially at night.
