There are 2 instances that use anti bot features that I could find. That is https://search.canine.tools/ and https://search.fredix.xyz/
Personally, the fastest and most reliable in my opinion are https://priv.au/ and https://searx.tiekoetter.com/ I used to use Tiekoetter's instance for nearly a year before I hosted my own. Otherwise I would recommend checking here: https://searx.space/
With that said, I still didn't answer your question, because I am hosting my own instance, but I would not recommend joining unless you really want to. I'm going to move it to central Europe, it's currently hosted in Romania.
They already had a controversy some time (years?) ago, saying stuff like "Bitcoin is all we need", "everything other than Bitcoin is a shitcoin", "we don't want to associate with the criminal record Monero carries"... something like that.
What you can do is to use non-kyc exchanges, send XMR in, exchange to Bitcoin, and withdraw directly to Proton. Proton won't be all hurr durr about dirty Bitcoin.