So I know there is a link that can give you access to the POTD system so you can go and find old photos you submitted for the contests, but is there a way that there could be a system that could generate a list of days and photos you submitted for each respective contest? I do not have a lot of my old photos, but would like to find an easy way to find them. Is there anything MM could do to resolve this, or do we have to settle on scrolling through every page until we find our photos?

You should probably re-post this in the Site Related Forum, where it is more likely to get moderator attention, since you're asking a question about the functionality of the site.

It's a good idea, and I would appreciate having that function, but since they shuttered the POTD, I find it unlikely that MM will put any work into new features that will help you navigate the archives of the contests.  I think it would even be nice if your portfolio page, in addition to the "See Credited Photos" tab, had a "See POTD Submissions" page, but like I said, I doubt anything like that would ever be implemented (we're probably lucky they even left the POTD archives up, hidden though they are).