I wouldn't feed yet, they look dark green and still well fed from the soil.
Until the soil has properly dried out a couple of times, the roots would still be exploring new soil pockets and have plenty to eat.
Hmmmm I've never thought of using perlite like that. It might work, if they wick up some moisture, as you'd be increasing surface area.
Interesting! Even if it doesn't work, that's not going to hurt. (unless maybe it makes the soil dry out even slower! Seems unlikely)
Lifting your pots off the floor can help increase airflow around the pots and around the drainage holes.
But it can be hard to find the perfect thing.
A big flat table the exact length and width of your tent wouldn't help, as it would block air. But a big metal grate on legs would help.
You can put them on top of upside down spare pots of the same size, or something small and individual to each pot like that - but it increases the risks of knocking one over.
It also doesn't help so much if your drainage holes are right underneath, better if they are on the corners.
I have some rectangular plastic baskets I can use for that. And a solid holey plastic seedling tray.
I've also switched to fabric pots the last couple of grows, which dry out heaps faster. (~$4 each on ebay)