What is Reddit's opinion of Plastic Pots for Plants, Cuttings & Seedlings, 4-Inch, 30-Pack?

From 3.5 billion Reddit comments

PLA is not biodegradable under typical conditions. It requires moisture and temperatures above 60C to begin self hydrolyzation. It will very slowly degrade in the presence of moisture at ambient temperatures, but I would be surprised if it affects the plants.

I use a bunch of PLA pots for indoor plants, but they're really just serving as a decorative outer shell. I do this with all of my decorative pots to protect them. I'll have the plant and soil in a 4" plastic pot with drainage (like these, for example), which sits snugly within the decorative pot.

I bought these last year. 30 for $8 and Prime shipping. https://www.amazon.com/gp/product/B0042KX77M/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

A little bigger than you were looking for, but your plants won't mind. They are sturdy, drain well, and should last me years if I keep them out of the summer sun.

Okay, so I'm trying to follow this guide.

Maybe get 30-60 4" pots of these. (How many should I get for 1500 seeds?)

I'm confused about step 5. They want me to pour the water onto the tray, then let the soil absorb the water all the way up to the seeds? The seeds are on top of the soil! Can the water go up that far?

If I put plastic wrap over them, don't they need oxygen? Should they be individually wrapped in plastic with a rubber band maybe? Since they're wrapped in plastic, is it safe for me to put it outside, on the patio roof? I'm in zone 10a. (SF-East-Bay-Bay Area)