As I've previously stated, I think it would be an extremely rare occurrence. but biologically not impossible. Proof? I have none. By your own admission, you have none either, other than speculation that there is no proof in your research on the subject. Also, I really do not care.
As far as more believable proof of a Sasquatch, I wholeheartedly disagree. All Sasquatch sightings seem to show very consistent, although blurry, appearances. Without DNA testing of those Sasquatch, it would be extremely difficult to know if they have a solid genetic lineage, They may have been watered down with the occasional alcohol influenced predator hunter at the turn of the century?
I'm not here to argue. Legitimately do not care. Time spent arguing these kind of things is pointless. I still have my opinion that it isn't am impossibility. You have your opinion that it just can't be. At the end of the day, we probably both have better things to worry about? Like getting out there and calling in these jokers and putting a well placed bullet into them. Maybe, when we walk out to pick them up, they will have some crazy appearance that will make us raise an eyebrow, and ask ourselves, what in the hell did this thing's ancestors do to cause this?