Catalina: Enable 32-bit, which 32-bit libraries to copy?

I am preparing to upgrade from Mojave to Catalina. But I must have 32-bit support. And it seems to be possible to re-enable. But the help is a bit dense (and badly formatted), like: http://netkas.org/?p=1491

Exactly which libraries etc do I need to copy from Mojave? And what's the path to those libraries.

I am posting this here rather than r/mac, as r/hackintosh has so many technically skilled users.