is it possible to do a small session, say 400 or so, without shaving the recipient area?
any insight will be greatly appreciated.

While it is reasonable to expect no shaving needed with 400 ....said differently, you are saying 1/4 inch by 6 inches ( I.E. 10sq. cm at a density of 40 per sq. cm). Why bother?

I don't know where you got the 400 graft figure from, but if you've already got hair in an area, then putting even more there in case you lose that native hair is not the way transplantation works. "Staying ahead of your hairloss" is not a phrase you should be hearing from an ethical doctor, and I doubt one would operate on you given what you're describing. Do you _have_ frontal hairloss? Do you know your possible final Norwood pattern? How old are you? These are all important factors, but what you've described so far doesn't make it sound like you're a candidate.

john,

I am also thinking about a small FUE procedure in my temple area to finish off what my first HT started… and shaving down the back was a concern of mine. Keep us updated if you find an answer to this, ill do the same…

"Reinforcing" is the wrong way to think about it. If you transplant into an area that's thinning but still has enough density, you could shock out permanently what native hair is already there, leaving you worse off after the HT than before.