truly think PF is a position of need because I see AD as the Center of the future
It would be a mistake to rush this. Davis is obviously not ready to play Center full time and making him gain a ton of weight will only hurt him as a player. He might still grow an inch or two, but I don't expect him to gain a lot of weight this summer. If he put on about 5-10 lbs of muscle this summer, I'd be happy. That'd put him around 230, which isn't enough to be a Center full time.
If you look at guys like Aldridge, Garnett and Bosh (all the guys I compare Davis to), it took them years to be able to play Center (mid 20's). Even then, their best position was still PF. I don't get why the team would move an all star, franchise PF to Center. I'd rather leave him at PF and let him thrive.