I think you could make a case for that and most would accept it. I would alter the statement to best scratch prize full stop. the division should be irrelevant if it is a scratch prize.So should support the best division having an addditional scrtach prize not offered to the other divisions then? Or would that be too much like "donating money"....
(My old view was that really good golfers eg the +2 mentioned, would have won more than their fair share on the journey to +2, which would have taken years of sustained improvement,with accompanying wins. But under WHS, thats not necessarily the case any more...)
The tricky bit is what % you award them out of the winnings. Enough to doff a cap to them, not enough to annoy the 95% who will never have a chance of winning it. I'm sure there will be a formula in use out there that has been used succesfully to do this, you just need to find what it is.