Hi all,
I've come to the conclusion that the best workaround for the lack of 64-bit builds on Mac and Windows is to run Lilypond in a Docker container. Based on the number of Lilypond images on Docker Hub, it would seem I'm fairly late to this party, though if it's been discussed on the user mailing list, I missed it.
When I have a chance, my thought is that the same principle should also work on Windows with suitable batch files.
I hope that official 64-bit builds for both stable and development will become available for all platforms, but in the meantime hopefully others will find this Docker approach helpful.
Happy holidays,
Saul