It does seem worth taking in to account that
a) your opus at least, you've had since before they were released to the public. The rocker shape could have been moderately tweaked since then.
b) you've been riding them a while, nose butters or whatever could have given the ski an extra cm of tip rise no problem!
What i meant by the way was that on my bacons the contact points when on edge, seem to be symmetrical around true centre, even though the sidecut is not. This has been true of most line skis i've skied in the past so it wouldn't surprise me.
This all strikes me as slightly irrelevant since no matter the exact rocker length, contact points etc, you have been skiing both Bacons and Opus at whatever point you've had them mounted at, and loved both. That seems by far the most important