This is very interesting. Thx. I have been thinking about building up a road racing type frame with an IGH. Maybe this is a foolish idea. But since I am already riding several single speeds with 70-74 gear inches, I thought it might be fun to have an 3 speed IGH or maybe a kick back with a coaster brake.
I put a Sturmey Archer S3X in a nice road frame - not full racing geometry, mind you, but the result was quite nice. It is nice to have some gear options. I think a 5 speed would be a good mix of gear range and weight.