Google remove supplemental tag

A site we're involved in has been in the supp index for a while due to some mistakes on our part and some on Google's part.

The site has around 300k pages with the vast majority in supp - they all used to be in the main index and attracted significant traffic (collectively) from long tail searches.

Now that we can't see which pages are in supp, we can't keep track of the main issue with the site - this is a major problem for webmasters or SEOs when trying to find problems with sites.

I think Google have done it to stop SEOs fixating on the supp. Google say that they're going to show more supplemental results in results but to my mind, anything in the supp is, in Google terms, low quality so why would they show these pages in standard results if there's anything remotely related in the main index? If they do this, they're admitting that they're showing low quality pages in their search results... strange huh.

It really doesn't make any sense to me so we're looking at creating a tool that will show pages that are in the supplemental index. I've got a few ideas and need to do some testing first but I think it can be done. I'm just a bit worried about it breaking Google ToS as we're going to need to scrape Google search results. We'd use the API but that's gone as well...