It’s cheaper to let all bucks with any sort of potential make it to 7 years old. It takes a few years of holding off. It’s amazing how big deer can get if you leave em alone a few years.
If you find no deer are getting mature then you saved yourself lots of time and money. When you can let em walk and see them grow bigger every year it’s time to drop protein.
My buddies family has a high fence place and I have not yet seen a deer peak later than 6.5yrs old. Many peak at 5.5. Waiting until they’re seven may be a slight stretch.
It can happen. Here are pics of the same deer at 5.5, 6.5, 7.5. He was killed this year...he added 20-25" per year between 5.5 and 7.5. Top pic is 7.5, middle pic is 6.5, bottom pic is 5.5. He went from 10 pt to 12 pt to 14 pt. It's not necessarily the norm to gain that much, but most deer will be bigger at 6.5 than 5.5.