I used to run an SRM with Rotor QXL chainrings with an Fluid2 trainer. Dedicated trainer wheel I used had an first gen Powertap Hub (wired, steel hub body) I threw together as my first (and only) endeavor at wheelbuilding. Note that this hub I bought on eBay on impulse 5 years ago.
Never did download the data from the Powertap computer but my eyeball checks with an SRM PCV and the Cycleops wired head unit side by side were pretty comparable. The SRM read slightly higher due to being on the cranks vs the rear wheel hub. But both moved in the same directions proportionally.
Also found an Power2Max Type S that I’m currently using to be pretty consistent with the SRM numbers compared to that Powertap hub as a reference (swapped due to going shorter crank arm lengths). Used the same brand Rotor QXL rings with both cranks.
My not so methodical comparison. Be interesting to do a DC rainmaker and also record on pedal based PMs at the same time too along with the smart trainer. But I don’t own that powertap hub anymore nor any other type of PM I can run concurrently on the same bike.