Would help if I looked up in left hand corner to view location. Sorry.
Yes, most definitely make holes in trays. If you can sit the seedlings (in tray) on top of another tray with something under it so that if water sits in the tray, it does not wick up into seedlings.
I use a few different fertilizers, 9-3-6 or equivalent, have used Cactus 2-7-7 throughout winter, then switched in summer.
Just use something similar. Do not push them now, just keep them active until spring when they can get more sun.