So there is no Modding planned (at this moment) for After the Fall
BUT I can understand why and I argue that this is actually 1 VR game where it's justified that the Devs don't add it in.
Unlike most VR games, this is fairly ambitious as it has crossplay with Quest 1, Quest 2 and PC...Normally I wouldn't give a shit and don't like Questies BUT I'm giving it a pass because of the one extra group they've added in Crossplay for, PSVR.
They are trying to do a Mini-Version of a "Metaverse" for their game, united no matter the platform. Which is honestly really fucking neat imo, seeing users on their PS4 VR headsets playin with PC users is really cool and kinda wholesome in a way.

So trying to do modding for this game, would cause issues with those other platforms.
You'd either have to cut the PC users out of the Crossplay, or make it so Modded lobbies exist, but that still breaks that "Metaverse" their going for.
Mods on Consoles are unheard of outside of Bethesda games, iirc it was only on the Xbox too.
Quest, I don't see Facebook playing ball with it.

And of course the giant problem is optimization for each of those consoles
No modder is gonna make variants of the same content for other platforms they don't use.

So yeah while it does suck that there is no Modding support and we may never have it for the game
I'd say that this is the 1 (ONE) VR game where it's at the very least understandable as to why not.