We don't provide support for Auctionator for classic. Its something for us to review in the future.

You can create an issue, but it will likely be closed without being resolved.

This just a question, is there a way to stop it from scanning every item I put up for auction? It has data from the full scan I just did, can't it use that?

There isn't currently. It is possible to tweak the code to get it to sometimes use the history prices, rather than always scan again.

I had a look at the code and made a change that does just that:
Auctionator-ClassicLimitedScans.zip