@operah I have an extension at https://www.reddit.com/r/operabrowser/wiki/opera/extensions/mask_as_chrome that removes Opera's part from the user agent so that Opera appears to be Chrome on whatever platform you're on. It works for all sites by default, but you can adjust that via the "site access" settings for the extension at the URL opera://extensions.
Another way to mask as Chrome is to goto the URL opera://flags/#freeze-user-agent, enable the flag and restart Opera. Then, there's no need for an extension.
You can also specify any user agent string you want for Opera via the command line as mentioned on this page.
Since it seems dr34polw is no longer engaged, I wonder if it would make sense for you to create a new extension.
Thanks. I thought about it, but I don't really want to keep updating the the user agents either. It's a never-ending task. It'd make more sense to have the extension reference a site like https://developers.whatismybrowser.com/api/features/web-browser-version-numbers that keeps the list of strings up to date. Not sure if there's a free list anywhere. That one cost money.
Not only that, but Chrome's x64 Windows user agent is the only one that's really useful in Opera. The other methods mentioned above already satisfy that. Also, this dr34polw extension allows you to specify a custom string right in the extension options in the user interface.
