The lack of tabs in #helixEditor caused me to open two instances on the same project. Unfortunately, it's written in #rustlang so the multiple rust-analyzer instances almost memory bombed my machine...

As the whole session started freezing, I wrongly blamed Firefox and started unloading tabs, but the fox was (mostly) innocent this time.

@bug have you tried https://codeberg.org/p2502/lspmux to make it only use one rust-analyzer?
lspmux

share one language server instance between multiple LSP clients to save resources

Codeberg.org
@laund someone pointed this to me, it indeed looks like it could be a workaround. But to be honest, I think I'm going to maintain a personal fork of helix with tabs support so I don't have to add workarounds on top of workarounds.
@bug ehh, it can be pretty useful even if you don't use it as a workaround for helix tabs, simply to persist the session a while after closing the editor. in that sense its perhaps a workaround for a oversight in the way LSP works, but its useful nonetheless