Very useful. Information should be free for all.

Alas it breaks login pages which use Cloudflare captcha!

I first thought that uBO and/or Privacy Badger are the culprit and disabled those, but then still could reliably reproduce the bug. Then I disabled *ALL* my extensions and enabled them one by one, meanwhile testing logging in. When I turned on Web Archives, login stopped working, I got an error message after entering my credentials and clicking the "I am a human" checkbox on the popup Cloudflare captcha.

Once I disabled Web Archives, login started to work again.

Mind you, this test was done with uBO and PB still being disabled.

You're better off just manually visiting the archive websites. Here's a suggestion, instead of opening a specific snapshot, open the snapshots (or history) page where the user can see (if) different snapshots and play around till they find the one that works. This will reduce the number of times the user gets "No results"