An update on my magnetic experiment from yesterday! Please forgive my cat yelling in the background.
Took this video a little over 24 hours after finishing my nails. As you can see nothing happened past the expected dispersal of the magnetic pigment once the polish cured.
I think I'll only be magnetizing the top coat from now on. It's worth noting that I did the same experiment with Cracked's Fermented which has a plain, dark red jelly base with goldish magnetic pigment. On the fingers that I only magnetized the topcoat of, you can see gold shimmer in the red base if you look closely or with flash. On the fingers that I magnetized all layers you can't see anything in the jelly base. However, the actual cat eye formed by the magnetic pigment on all fingers is extremely similar regardless of which method is used, so despite some magnetic pigment clearly being left behind when magnetizing only the topcoat it doesn't seem to be an amount that effects the overall magnetic effect. The visual difference in the base if you're not staring closely or under direct flash is negligible to me. It should also be noted that Fermented's base is a very vampy red, so I think the magnetic pigment that is not pulled when only magnetizing topcoat would be more apparent in a polish with a paler or sheerer base.
As a reminder, the coats I did magnetize I did so for 1 minute, and I waited until each coat was "touchable with no strong fingerprints" dry before adding the next coat.
Thumb is 2 coats magnetized and Sally Hansen red bottle magnetized
Pointer is 1 coat unmagnetized, 1 coat magnetized, and Sally Hansen red bottle magnetized
Middle is 2 coats unmagnetized and Sally Hansen red bottle magnetized ONLY
Ring and pinky is 2 coats unmagnetized and Essie Gel Setter magnetized ONLY
Base coat is Cracked Ridge Filler and polish is Cracked Gherkin.