Rivendell did state that the 2020 had more clearance. Mine is the 1st generation but will still fit 38mm tires.
I meant that I need to instal the tire deflated to get it past the brake shoes even with the caliper open.
Also, some orange frames from the 1st batch apparently had the brake bridge welded too high which allowed bigger tires but almost made it so you would have to use a long reach caliper instead of a standard.