Beginner question!

On regular experimental releases, do i have to create a new world/character to utilize the updated features, for example, ammo vending machines?

I haven’t played for long enough to give a crystal clear answer but the one I can give is that you probably won’t, unless you discovered the vast majority of the map.

Already generated areas keep their old stuff.
Areas you haven’t visited yet but within the same overmap will have new stuff, but some of the old buildings and monsters.
Areas in new overmaps are almost entirely new.

You can check overmaps on map screen: those are the “big” coords - one overmap is 180,180 of map tiles.