Can't see MainStage/Logic instruments in GarageBand

I recently purchased MainStage (Version 3.5.2) primarily so I would have the MainStage/Logic instruments available in GarageBand. (Version 10.4.3 running on Big Sur - 11.3.1) I downloaded the MainStage sound library when prompted (9 hours, and after 3 failures I realized I had to be available when the download finished to provide the admin password for installation or the installer would timeout quickly and I had start all over again !). I confirmed in MainStage that the instruments were downloaded and available but can't see them in GarageBand. I hit: GarageBand -> Sound Libraru -> Reinstall Sound Library (another 7 hours but at least the installer waited for me in this case). But that had no effect.

I noticed that the MainStage/Logic instruments appear to reside in /Library/Application Support/Logic/Sampler Instruments but nowhere under /Audio or Library/Application Support/GarageBand (and there are no links).

Any suggestions appreciated, e.g. do I need to copy the files from /Library/Application Support/Logic/Sampler Instruments to /Library/Application Support/GarageBand/Instrument Library/Sampler/Sampler Instruments ?