If you flat with tubulars and ride it out, you'll still mess up the rim, you just have a lower likelihood of crashing. Ruined a wheel that way after reading all about how it's ok to ride out a tubular flat.

Yeah, you have to be careful. I'm just talking about slow-rolling back into the wheel pit in a crit, though. Not about doing any real riding. You're right you can still ding up a rim that way - just much easier to not be rolling bare-rim-to-asphalt with a tubbie.

Doesn't it depend on the tyre? My Corsa Speed's I can feel the rim and can barely ride it, no more than 5km/hr, my Conti Attacks I could probably ride at 20km/hr and it feels like it's heavy duty enough to protect the rim.