We're literally running this on a hobby-tier Heroku dyno, with free-level redis and smtp services and doing fine at the tens-of-requests-per-minute rate. So you should be able to host your own! :) Once we implement https://github.com/portier/portier-broker/issues/88, it'll even be a 2-click process to get going.

We do intend to keep https://broker.portier.io online as a public service / reference implementation, but we don't have anyone on call or anything if it falls over. On the upside, the Broker is written in Rust, so it shouldn't segfault all that often. ;)