This might be a case where a power meter with independent readings for each leg would be of some value. Garmin Vector will tell you the percetnage of power from each leg.

Newer Quarqs don't have true independent power, but break the pedal stroke into halves, and tells you power for each half.

Rather expensive, but if you do have descrepency, it would help you work on it.

One legged drills might also tell yo if there's an issue with your pedaling that you need to work on.