Would it work in reverse and give us total tandem power?
If you want to measure total tandem power, you need to measure at the final drive, either the rear hub or the stoker's crank spider.
The difficult thing to measure in isolation is stoker power, you either have to measure at the stoker's pedals or use two PMs and subtract the driver's power from the total.
Get a pair of garmin vectors. One pedal for you, one for stoker. L/R balance will give you the load split So you can see how much harder you're working at the front ;)
If you want to measure total tandem power, you need to measure at the final drive, either the rear hub or the stoker's crank spider.
The difficult thing to measure in isolation is stoker power, you either have to measure at the stoker's pedals or use two PMs and subtract the driver's power from the total.