It is a good looking frame and there is nothing wrong with a double butted 4130 frame for a bicycle of this type... it probably benefits the frame in making things a touch stiffer and adds some more robust tubes.
I like it when frames have threaded bosses on the chain and seat stays, but not that VO has left this open up top as it seems like a great place for water and dirt to enter the bridge.
If it was me I would make the fork a little more useful / versatile by adding lowrider mounts and a second set of eyelets. I don't like socket dropouts as although they speed construction and look cool, they are a pita when you have to make a repair and horizontal drops would also add some options for an IGH drive.
But then that is just me, and if I wanted a frame like this I'd just fire up the torch.