Quick Q, Does eRX have a button that can control the head unit screen like Di2 (Ultegra+) has? 

To clarify, with Ultegra and DA Di2, there are buttons on top of the hoods that can be programmed to page up/down on your head-unit.

late to the game, but I'm a happy Spcycle customer.

Bought an SP R-05 frame spring 2021 (I think it's now SP R-06).  Only real issues were related to the braze on derailleur hanger (popped off and I had to re-rivet) and I needed to add a spacer (pedal washer) between the chainstay and rear wheel end cap as the chain rubbed against the chainstay. I'm using a wheels mfg threaded BB.

The bike has survived two semi-serious crashes (broken bones) and the company even sent me a new derailleur hanger for free after the 2nd crash bent the original.

Carrie always responds quickly.

(ignore the dirty drivetrain in the chain pic ... it's now perfectly clean and waxed as in the other pic)