Belt would look similar to this:
Every corner of the belt counts as the inner corner of a belt at a bend, and items would flow as such.
I feel like such a tile would allow for some interesting design opportunities, and offers an alternative belt-based solution to splitting one half of a belt away (currently the only belt-based option is underground belt mechanic abuse) and allows using both halves at once from a single belt feed. Currently, the only alternative is to use smart inserters, but for higher belt speeds this gets cumbersome.
I'm not sure this is even feasible given the current state of modding (it looks like you pick a functionality set and go from there), but it's probably worth discussion regardless.