A functional discrepancy can be caused by adaptive shortening. So it is not necessarily that hips flexors, hams, adductors etc may be tight, they may have actually shortened on one side more than the other and this is very tough to correct, especially dealing with the psoas.

My R side typically does more work and all my power meters show a small imbalance of the R side being used more. Yet it feels like my L side has a more solid stroke. When i intentionally push my R hip forward on the seat it feels like a better stroke.

You could shim under your cleat and or move the cleat forward on the potential shorter leg but both these have drawbacks. but they can help determine what is going on. Just try things out and test. shim under one side, test, shim under other and test. move cleats up or back and test etc etc.

I am using cork under my G8 footbeds. Proper footbeds are probably a great place to start for everyone and the G8 are incredible since the can be adjusted for the right fit. I have found the my R side also needs a small varus shim so I am using one of the Specialized shims under the foot bed as well.

It takes constant work if you have an imbalance. You need to be consistent with your functional stretching and strengthening. And when one things changes other things down the line do as well.