lib32: install-time, lib32.txz, FreeBSD-set-lib32?

[Espionage724]

Installer has a lib32 option in Components, there's lib32.txz that can be manually-extracted, and pkg install FreeBSD-set-lib32 can install a bunch of lib32 stuff.

Is there a difference between any of them? Is installing FreeBSD-set-lib32 post-install the same as selecting lib32 install-time?