But even if you get a higher dose per unit of time, you spend less time in the air so your overall dose is lower. Your link mentions that. I guess the main exception would be for personnel that did a lot of flights. That could be reduced by requiring longer ground breaks than with subsonic aircraft.

The amount of radiation you receive during a regular flight is quite small, and more than you would receive on a supersonic flight: https://youtu.be/TRL7o2kPqw0?t=307

Right, that's something I was wondering when Boom was announced a few years back [1]. Will radiation be even worse for the crew if the plane body is made of carbon-fiber vs thicker metal like the Concorde was?

[1] https://news.ycombinator.com/item?id=12791122