Re: 1020 trays. These looked pretty good, too - I watched the video - they look flexible and sturdy. 10/$26.99 with very good reviews. If you have Prime (which I do, living rural with not a lot of shopping options) shipping is free.
RooTrimmer 1020 Nursery Trays, Heavy Duty Seed Starter Tray
These are stronger than the current crumbling ones I have on hand, for sure. I have plenty of recycled nursery pots in many sizes, plus I’ve started stashing cottage cheese/yogurt/sour cream containers thanks to a suggestion from MomWithHope. :)
All I use now are old small yogurt containers the larger cottage cheese ones, and if I buy a small nursery veg plant I reuse those. Can’t type much. Had a fall outside. Not too bad.