CodeTogether has multiple platforms but I'm not sure if it allows different clients to connect together
(And I was thinking this would be OSS CodeTogether)
For example, I can make do with intellij whose vim plugin is actually well made but the vimlike plugins for vscode are all useless.
The streaming quality was also quite good with Zed. VSCode and JetBrains pairing features were a pain, as you needed to share a URL. The experience in general was not optimal. Not something you want to do multiple times a day.
With Zed, the only drawback was that the scope is always IDE (view mode also for whole screen). But from my experience, pairing is more than your IDE. It's terminal, debugging your unnecessarily complex AWS setup, fiddling with Grafana dashboards, etc.