I was only aware of Helion doing D-3He, and they're in Washington. Do you have a link for the Princeton group?
The small company proposing using this for a notional Pluto orbiter:
Primary patent for the reactor:
The scheme involves significantly non-maxwellian ion distributions, so "temperature" isn't really appropriate. In particular, 3He ions get pumped to higher energy than D ions, which helps suppress DD fusion. They claim the scheme is consistent with Rider's limits on energy circulation in non-maxwellian plasmas.