I don’t think this would make mini_roundabouts obsolete. These still perfectly suited for small intersections with single-carriageways, like the examples on the wiki. But this intersection is larger than all of those examples. I think mapping it as a way makes for a much more useful map.

The other possibility I thought of would be to make it more like a T-intersection, like other T-intersections of dual carriageways. I thought this might be appropriate because the road markings on approaching ways are more similar to a T-intersection than for a roundabout.

Do either of these options appeal to you?

Ugh, looks like the weirdness continues. Sorry for the redundant uploads.