Earthquake! I own two Radii, one of which I mount at the twelve o'clock position looking over the day optics, the other of which I mount at either the three or nine o'clock position below and left or right of the day optic's line of sight. I would recommend that you "co-align" your Radius with your day optic at its base zero. For example, If mounting at the twelve o'clock position looking over the day optic, measure the distance between the day optic's centerline and the laser emitter on the front of the mounted Radius. Using the Radius' aiming laser in a low light condition, use the Radius' adjustment knobs to "co-align" the Radius so that the aiming laser's downrange strike is the same distance over the point where the day optics crosshairs lay on the target. If done correctly, as long as the Scope is adjusted to the same base zero, the Radius will range to a point the same distance over the point at which the day optic's crosshairs lay, regardless of distance. In other words, if the distance between the mounted Radius' laser emitter and the day optic's centerline is 2", at the day optic set at a given base zero, the aiming laser should be the same 2" above the crosshairs at 100, 200, 300, or 1000 yards downrange. The same methodology is used when mounting the Radius at 3 or 9 o'clock position, but the horizontal offset of the Radius, as well as the vertical offset of the Radius must be accounted for.
Once "co-aligned", I have taken the additional step of painting a "witness mark" at twelve, three, six, and nine o'clock onto each Radius' elevation Dial and Twelve o'clock on the Radius' Windage Dial. Noting the clock positions where the witness marks line up and the turns to get there, I co-align the Radius On different weapons and use the data to mount the Radius on a number of different weapons.
It is important that the tension of the Raduis' rail mount is tight. Adjusting the rail mount so that one gets the same "feel" when closing the lever on respective weapon's pic rails, I have been able to achieve significant "on/off" repeatability of co-alignment.
Once I am satisfied that the Radius is properly co-aligned, I look thru the day optic, note where the Radius' aiming laser overlays the day optic's reticle against a downrange target, and record it as well.
When moving the Radius from weapon to weapon, I start by lining up the painted witness marks to their noted positions to achieve a "gross" co-alignment. Once done, I make minor adjustments to achieve the aiming Laser - Reticle relationship previously noted to get a more precise co -alignment. After dark, If you have NOD's, you can " see" exactly what Radius is ranging by witnessing the strike of the pulse when triggering the laser and make fine adjustments from there.
Hope this helps and did not confuse you
Semper Fidelis
JHC