Bethesda edition relevant data

What data is exactly required from the 2021 “rerelease” in order for the game to work with one of the community-based sourceports? I believe just the “pak” files, right? The fluff with ‘KEX’ and ‘Steam’ and other “dll” present in the game folder are useless?

EDIT:

Apparently the localization thing will crash without “QuakeEX.kpf” file.

You can use either original or rerelease id1 folder. The rerelease id1 folder obviously has higher quality sounds, different progs.dat (for example, Nightmare skill works differently) and recompiled maps with slight touchups here and there (most notable is restoring of e2m6 starting area). It also probably has the additional extra data too, like colored lightmaps and md5 higher detailed monster models.

Alongside the exe of your sourceport all you need is just QuakeEX.kpf, and even not everything in it is needed really, just the localization strings. Because the rerelease maps and mission packs all refer to strings from it.