EDIT: Editing the page with some of the ways to disable autocomplete [0] don't seem to be working but I'm not sure if that's because 1Password binds at page load and doesn't care what I change using DevTools. In the end this is clearly 1Password's problem [0] but I sympathize with them even as I am negatively affected by it. If they had an attribute (like lastpass) we all know the worst websites/offenders on the planet (banks, intranet sites, most financial institutions, most site asking for routing/account numbers, etc) would abuse the hell out of it. It's bad enough when they try to prevent copy/pasting in. I do think they should at least provide a way to blacklist sites where you don't want to use 1Password.
[0] https://stackoverflow.com/a/51686510/1072106
[1] https://1password.community/discussion/117501/as-a-web-devel...