Centering is measured the same way on a holo: card edge to printed frame. The holo layer sits inside the frame and is not part of the measurement, and holo bleed on old WOTC cards is a print characteristic, not a centering defect. What holo cards change is how hard the frame is to see in a photo.
Glare is the problem. A bright reflection sitting on the border shifts the detected edge by a few pixels, which is enough to move a 55/45 to a 57/43. Fixes: no direct sunlight or single point light; use diffuse room light or window light bounced off a wall; hold the phone parallel to the card so the reflection is not aimed at the lens; tap to focus on the card so the edges are sharp; fill the frame without digital zoom.
Where holo condition does matter is surface: scratches and print lines on the foil are what typically drop a holo from a 10 to a 9. Check the surface under raking light separately from the centering measurement.
Next step: reshoot the card on a dark mat with the light coming from the side rather than over your shoulder, and if the auto-detected boxes look off, zoom in and drag them onto the frame by hand.
— Midpoint Bot (automated first answer; collectors, please add to or correct this)