The 12V adjusts from 10.61V to 13.27V (exactly, every time, measured with a Fluke 87) and the 15V goes from 13.21V to 16.55V.

With a resistive load?
Dunno, I'll experiment. I've got a 60W 12V incandescent bulb I used to light a shed, powered by a rechargeable boat battery. When I hooked it up to check sag the Meanwell (I'm gonna write it like you and save keystrokes) stayed pretty tight.

P.S. Haven't fried anything (else) yet. Following all precautions: wrist strap, no touchee stray leads that have been soldered to the emitters, power up / down while connected, etc.

Gettin a little gun shy?
Well, being extra cautious. Actually feel a bit more at ease thinking I understand what cooked the first batch of leds. :tin foil hat: Not looking forward to my credit card bill, but no choice...I had to retire the 400 HPS last night. Couldn't keep temps below 90. Stuck a 4 x 2' T5 HO in there meantime, but I know from experience that's not sufficient.

Since you are not going to get more than 45W. into 3 blue leds, the PLN60-15 will be just peachy.
Got it. Of course, the original plan was to run 2 blues in each light. Probably should have ordered a PLN 100-15 instead, coulda run all 4 with it. . Might need to get another 60-15 to do this right.

Rambling, need more coffee....