I’ve used hydrogen peroxide at concentration of 1 part 3% h202 to 7 parts water, for reviving droopy or over watered plants that are in too dense soil, it works great for this even though your drenching the medium with more water the h202 gives them a boost of oxygen and from what I’ve seen the plants usually bounce back if left to dry back out after 3- 4 days after the h202 drench.
I’ve also used .5% solution on droopy clones that were put in too wet rooters, and it seems to help.
I might try feeding h202 every other watering during flower just to see how it turns out.
Every time I’ve used it the plants seem to react positively to it.
Sometimes I’ve done the .4% h202 drench as a first part of watering, wait 10 mins, and then finish watering with nutrients.