Depend on many factors, and it’s basically, how each of the extensions can modify your web browsing. From your current configuration, I suppose KeePassXC would be causing no issues, except if it supports any kind of protocol (Like a web button “open in app” button) I could imagine, or maybe a less trivial way to input stored passwords which could differentiate from a user typing it, and copy-pasted it (An user typing automatically, a 64 random character passwords at less than 1ms per stroke is suspicious). Dark Reader, however, should be fine as well, if it doesn’t try to send any “dark mode preferred” headers, as your browser should already handle that (And the Tor Browser should already enforce keeping light-mode to stay common enough) However, That’s more of an issue with uBlock Origin or most Ad blockers, as they tend to directly block any known content types or direct ads domains before your browser can contact them. Which could make a website, easily check on a list of common domains, or content types, if you block it. You can test it here, and yep. uBlock Origin fall for it. https://browserleaks.com/proxy

You can learn more on that in this blog post : https://fingerprint.com/blog/ad-blocker-fingerprinting/