Is there any ways with SMF 1.1.# to make a Mature/18+ Board that would use age verification or something to that extent?
Not for p0rn or anything, but a board that things considered NSFW or someone under 18 shouldn't have access to.
there is no real useful way to do that as people will fake their age. and you would need a mod to even attempt that so you should go post in the mod requests board if you really want this feature.