There’s a pretty big difference mechanically between how Garmin vs Favero are built. Favero uses an inboard pod, pushing the pedal out and giving room for the electronics and the strain gauges, but allowing the use of what appears to be a fairly stock pedal body. Garmin has an overlapp between the pedal body and the strain gauges, forcing relocation of bearings compared with a “standard” pedal - and thus the pedal body is not the same as any other pedal on the market.
Thus the stock-to-stock pedal body swap idea may work with Assiomas, but is not applicable to Garmin Vectors.