Off topic question: does anyone who is using jetbrains spaces know if it supports real time collaborative source code editing ?

I don't know for sure, but I think it does not. But IntelliJ now allows it, or better said it is in official beta and probably soon will support it.

They recently added real time collaborative documentation editing, so maybe it's the next step, but I haven't seen anything mentioned about it. As @Vampire mentioned the ‘CodeWithMe' plugin (by JetBrains) allows real time editing in the IDE

Nice, thanks!