Are you sure about that? I know that 16x 32dif shares will pay out the same as 1x 512dif share, but when we hit those blocks that simply fly by without any solved shares wouldn't it be better to get a few 32dif shares in? Or is it simply about solving blocks at that point making shares irrelevant?
Sorry if this has been discussed already, I haven't had time to read this entire thread.
If blocks come frequently, that doesn't make high difficulty shares any less likelier.
It increases your reject rate, but it does so equally for high difficulty shares and low difficulty shares.