I'd suggest just being an honest broker and letting people know the truth. Am I going to say that when there was a possibility of me returning to full duty and unrestricted flight status that I didn't mince words with my CO so I didn't get a crappy fitrep? No. I told him that if I returned to full duty, I was staying in. I was pretty sure I'd never return to full duty. So was that a lie? I'm not a doctor. So to me, no...
Later, I was advised that if you say that you "wish to continue" military service, the PEB will go through great lengths to find you "fit." Take into account what you're rank and grade require. Where I am, I can't hand out towels at the gym. This can definitely bite you in the ass because when you can't perform your required duties (billet related, PFT/CFT, body composition, etc) you're looking at problems - which potentially could lead to ADSEP. Then you're looking at only VA compensation.
I had nearly every flight leadership designation and qualification you could have in my plane and as a pilot I worked really hard to get there. I wanted to stay in - almost to the point of hiding my conditions. But at the end of the day when you ultimately separate from service - you're the one who has to deal with your physical and mental conditions. Take care of yourself and your family, it's not selfish to do that...