This idea is purely speculative and would require further investigation, which I will leave up to you. One approach could be to identify a CSS rule that is typically altered by plugins and use JavaScript to check if it has been changed. If the change is detected, you could kindly advise the user to disable the identified plugin. Some plugins, like Dark Reader, have whitelist features for specific websites. Keep in mind that this suggestion has not been tested.
For Kiwi Browser users, consider detecting the user agent and providing a warning specifically tailored to them.