Could you guys add tags for most of the land-dwelling creepers so they drop Creeper Spores
And if possible add a Creeper Overhaul-like texture to the creepies spawned from spores

Since both mods are really fun, I'd love to see them interact

No plans for support for this, we encourage someone to make a datapack and/or mod for support though!
Creepies use the whatever texture the regular creeper has