We have been feeding protein for a few years now on 241acres in south Texas low fence. We have noticed our deer population getting larger and deer seem healthier. It may be due to a few wetter years though. We have had our place since I think the 70s.
We now are managing age, feeding protein, have waterers, pens on feeders, plant food plots, and feed year round. The neighbors don't manage except for age but don't hunt much and there's not a lot of them.
I doubt we will see a huge difference ever, but we enjoy it and you can't take you're money with you when you're dead...
Is it wort it...idk yet.