Vertex count and smoothing groups

If I'm not mistaken, that sounds about right when you consider that vertices have only a single UV coordinate in Unity. Essentially, anywhere that you have UV seams, you would also have a unique vertex per shared position.

Using a basic cube unwrap as an example, you should have ~14 vertices at a typical minimum.

Extrapolate that out to a cube with beveled edges and its (rounded) base of 24 vertices (as opposed to the 8 on a cube that are transformed into 24 for flattened faces) will expand out by the number of cut edges...

So, yeah... Mid-30's sounds entirely plausible.

I think its the default 24 vertices, plus every UV sharing the same world position but different UV coordinates creates a new vertex so that's 8 more. (32 vertices)