I think pedaling metrics are useless. I don't think knowing a percentage matters in the least, and I think worrying about it is a waste of time.
With all that said, I definitely think pedaling indoors and outdoors is just different enough for some people to be noticeable, and I've struggled to exactly qualify why. I almost always have left-knee and left ITBS tightness or "niggles" riding inside that I never have outside, even if it's just for 30-45 minutes. Could be shifting or not shifting weight, sitting further forward, or maybe even my trainer is just slightly off-level (I've even tried cardboard under a leg at times), but something is a bit off.