I've run 1x drivetrains on two Rivendells, but not a Roadini. Both of them were a 42-tooth chainring and an 11-32 cassette.
I had that setup on my Sam Hillborne, and used that for all-purpose road riding, including a 200k and 300k brevet with San Francisco Randonneurs. That setup employed a friction stem shifter, and a 9-speed cassette. I'm in the process of swapping that out for a 3x9 because I'm going to be using that bike for a loaded tour.
I also have a 1x10 drivetrain on my Legolas. 42-tooth ring, and a SRAM 11-32 10 speed cassette. SRAM double-tap shifter, Force clutch rear der. I had that bike out yesterday on a 40 mile mixed terrain ride with 4000 ft of climbing.
A 1x drivetrain can be great.
Bill Lindsay
El Cerrito, CA