[Q] Htc Advantage Lose S-Off topic

So I am in the last month of my Htc free screen replacement. I have read many of the posts about people dealing with HTC and the success and fail stories. I have decided it's worth the risk since my crack is pretty bad. I'm S-Off, Bootloader unlocked and was wondering if I flashed a modified h-boot to show the device as S-On and bootloader locked and restored the stock Recovery, Rom, and Kernel would they be able to tell that the device was modified? If they are able to tell and deny my replacement I'll just keep the phone and have it replaced at a shop but it would be nice if it was free. Also if they update the phone will I lose my S-On and Bootloader unlock? Thanks