Proseal T-708 tank stiffening ring?
 

Fuel tank stiffening ring for access cover. Plans say sealant not needed, but I keep hearing “Proseal is cheap at this point”. I can understand why it’s not needed as the whole area will necessarily be sealed later - any reason to seal it?

Thanks!

Your choice.
I chose to seal it on all the tanks I did. Same reason I choose to lay a seam on all inside flanges.

I didn't seal it. Once the access cover goes on and is sealed as per plans you shouldn't have leaks from that area.