I tested the sysimage branch on MacOS, it seems to work and indeed accelerate the startup time.
Not sure whether it matters but I tested it only on a mock project .
I am having some problems with the language server crashing on a real project (not related to this branch) which are probably related to LanguageServer.jl. I will try to open an issue. Is there a way to make eglot to not reconnect after a server crash? I would like to provide the relevant details from the event buffer but eglot just keeps reconnecting (and the server keeps crashing) swamping the event buffer with new info.