Supposedly squash are a little particular about drainage and not sitting in water at all, so a mound ensures better drainage. *SHRUG* The local U-Pick pumpkin patches don’t grow them that way; they just fill the fields up with plants, LOL!
The BEST way I’ve found to grow summer squash (and I guess you could do this for winter squash, too) is to dig a hole and insert a nursery pot (with holes) into the hole. I use a 2-gallon size pot, so that goes down a good 8-10” into the soil. Then, I plant my seeds (or started plants) around the pot, N, S, E & W, four plants. I water the plants in, but after that I water and fertilize right in the pot.
I have grown amazing zucchini and patty-pan squash that way, and no problems with blossom end rot or anything. Pick often, because they grow really fast, too!
This caught my attention...you are taking a plastic 2-gallon pot filled with medium...placing the seeds at the four points of the compass in the medium...and placing the whole shebang into the ground up to the rim of the pot? Crowding doesn't become an issue? (4 plants in one 2-gallon pot...)
I would like to try that if I understand what you are saying...I am starting squash/cucumber plants in 4-inch 'dot pots' that I can plant directly into my raised beds; just to get a two-three week jump on the short New England season. I am also thinking about trying squash/potatoes/melons in straw bales this year...obsessed with trying 'new things'...