Feeding, under a light, is not the way to go ... even, more so, if the pink is in a bowl (where a hatchling would have to climb ~in~ rather than, easily, sliding ~on~). If feeding in its enclosure, it is, also, best that the feed is placed at the hide's location ... like the hide's entrance.
Mutilating, as you say, a live pink is out of the question, as far as I am concerned, so can understand your not wanting to do this (I wouldn't either). However, cutting a frozen pink does not bother me since, at that point, it is just a carcass (just "meat" and not a living/breathing critter).
Would you have a problem cutting a frozen/thawed pinkie?
I had a newborn refuse his meal and would not eat while in a deli cup either.
Since newborns (and young hatchlings) are kept on paper towel, I decided to feed him by placing the pinkie at the entrance of his favored hide and leaving him, totally, in peace & quiet. Before placing the pinkie there, I gutted it (deflates the "chubby" belly making the pinkie even smaller... & guess it adds a further scent too). This worked. Move was made on to whole (non-gutted) newborn pinks without incident.
Some folks will cut off the pinkie head and just offer the head (its being smaller than a whole pinkie) until the hatchling is, reliably, eating. That, or a pink is cut in half (best done while pinkie is still frozen).
Other suggestions:
Braining the pink may work (you can do this with a f/t, it need not be live).
Warming the pink may work.
Leaving hatchling, overnight, in a deli cup, along with a pink (f/t or live), may work.
Scenting the pink may work (scenting via commercial product or rubbing pink on a lizard, or with mouse bedding <not urine/poo soaked bedding>, etc.).
Dipping the pink in chicken broth may work.
Washing the pink may work (using mild soap & making sure it is well rinsed).
Would suggest trying live, if it has only been offered f/t, but .. it seems you have tried this.
Of course, you can do a combination of the suggestions ... like warming ~and~ scenting, or washing ~and~ warming, etc., etc.
Remember that each snake is an individual. Therefore, you may have to try different things because ... what may work, for one, may not work for another.
Keep in mind, too, that temps could play a part, as well, but I am assuming that your viv temps are correct/appropriate.