I'm pretty sure it's entirely disabled. Their announcement post says it's being removed and doesn't call out any exceptions.
I run my clients through a gluetun container with forwarding set up and ever since their announced end of support date (July I think?) I have had 0B uploaded for any of my trackers.
E: realized you may be asking about proton, oops
Yeah I've been using it for about a year and half or so on my main devices and it's been wonderful. I'm likely going to down the list of supported providers from the gluetun docs and decide from there. Throwing my torrents and all that behind a vpn was the catalyst for signing up so I'll continue to look for that support first and everything else is secondary.