Didn't iBike try and do something similar to those Pods about 10 years ago?
There's also BB-based PMs, I owned a Polar chain-based PM, someone (Bebop?) tried to make cleat PMs, etc.
If you're going to spend money on a PM, get a proper PM - Powertap, P2M, SRM, maybe Qarq, InPower, etc.
All of the cheap ones are usually limited to guesstimating steady-state power at best and fall apart whenever anything peaky needs measuring and if a job's worth doing...
I'm waiting for the full bike-mounted aero test suite to come out...