Retrofit RoG content to old worlds

[shadowDigga]

I have a really old world back from 2014-2015 era that I recently returned to and I'm really saddened that I have all of Return of Them and most of New Reign stuff retrofitted in that world while lacking RoG content such as Desert and Decidious with associated mobs like catcoons, moleworms and volt goats (not to mention lack of cacti and tumbleweeds). As such, New Reign content that's supposed to spawn in these biomes - Antlion, Dragonfly, Klaus, Deers and Oasis - are missing permanently.

Since I believe it was impossible to retrofit new biomes back then, it would be nice to make it possible to get those now that even caves can have large lunar glotto + ancient archive island added into them via no-sanity wormhole. I totally wouldn't mind having decidious + desert island accessible some distance away from mainland, be it via wormhole or boats, to not having it at all. Please.