Welcome, You seem to be doing a good job so far, not much to change with your setup. If sheds are broken you can increase the humidity just a little; either reduce airflow by covering up 80% of your screen, larger water dish or mist cage when you notice your snake is in shed. It’s ok for temps to slightly fluctuate in a day/night cycle and I’ve read night lights might stress nocturnal snakes like your milk snake, might want to switch back to using the under tank heat mat instead. Keep your day light on a timer and heat mat regulated with a thermostat controller. You can find plenty of care videos online, good luck!