If you are on the preview rust-analyzer releases you can now enable using multiple proc-macro servers (or on stable next monday) by setting the `procMacro.processes` config to a higher number than one 1. github.com/rust-lang/ru...
github.cominternal: Parallelize proc macro expansion by Shourya742 · Pull Request #21385 · rust-lang/rust-analyzerThis PR replaces the single proc-macro server per workspace with a small pool of server processes.