Attempting to open the library results in indefinite loading. The plugin doesn't stop to load, so I have to shut down the DAW.

This is the library: https://www.pianobook.co.uk/library/autumn-piano/

I believe that specifically those libraries made by Christian Henson use a less common method: monolithic audio file with no separate samples per note, but one file containing all the notes with specific timestamps being referenced in the mapping. There seems to be a similar issue when loading the Decent Sampler version on that platform:
https://www.pianobook.co.uk/forums/topic/having-trouble-with-christian-hensons-samples-in-decent-sampler-format/

VST 3 version on Windows, Ableton 11