I get 8.44 bits (1 in 347.34 browsers). I use Firefox with Arkenfox user.js applied on top, with some of my own custom overrides.

However, I think the biggest factor could be because I have Ublock Origin set to medium-hard mode (block 1st party scripts, 3rd party scripts and 3rd party iframes by default on all websites), so the lack of JavaScript heavily affects what non-whitelisted websites can track. I did whitelist 1st-party scripts on the main domain for this test (coveryourtracks.eff.org), but all the ‘tracker’ site redirects stay off the whitelist.

I actually had to allow Ublock Origin to temporarily visit the tracker sites for the test to properly finish–otherwise it gives me a big warning that I’m about to visit a domain on the filter list.

Also worth mentioning: osu!lazer has a native Linux build, whereas osu!stable still requires WINE to run on Linux. That’s something I was very glad to see.

Use Mullvad, unless you absolutely require port forwarding.

As another commenter said, it’s not possible to verify. You’ll just have to take each instance’s word for it.

Instance lists for some privacy front-ends will point out additonal info, such as if each instance is using CloudFlare or not (this may or may not be useful depending on if you distrust CloudFlare), some other services (like Rimgo, a private Imgur frontend) lets the instance hoster customize the privacy policy. But once again, this is all relying on the instance host telling the truth.