Yeah, but it can be very messy material as you know and affected by rain etc. I agree with John though, it might look `odd`if he comes too far forward with a partial or fills in that area fully at the temples--- a certain amount of recession there is natural/normal as a person ages. The guy looks to be not very old, but there is thinning apparent in the centre back towards the crown area but at least if he acts now with a small partial, and maybe needs more coverage in time, it will be a lot easier for him to make the transition without worrying about attracting `` attention``.