Loading libraries is increasingly expensive to load with each new library and symbol
I've have been disturbed by how long loading libraries can take in eeschema. I can easily observe 30+ seconds of the dialog. Under MSVC in debug and I guess due to profiling tools, it easily takes a minute for me.
Profiling the problem. 95% of the loading time is spent in SCH_LEGACY_PLUGIN_CACHE::LoadPart
This function call is attempting to parse the library and all its sub symbols. So long term this becomes a linear growth problem as the library team keeps adding more libraries and symbols.
I can only suggest that perhaps the library loading is changed up. Upon loading the library editor, the first thing it does is only display library names. The user then upon expand of a library in the editor/selector will cause kicad to load the symbols in. This would be far more efficient than one giant heap.
Related to #4563 (closed)
And I also assure you I am definitely not IO or cpu bound when I can build KiCad from 0% in 4 minutes and 30 seconds ;)