Anyone here ever try build-a-soil?

I’m about to run 4 seeds in a 4x4 in some 3.0 Recipe from Build-a-soil. Anybody have experience with that? Not sure if I should go right into the final pot or start in a 3 gallon then transplant to a 5 so I can fill it with more 3.0 so I don’t have to amend

I like to match the size of the pot to the size of the plant. I find my plants respond positively to transplanting.

I have some that I am keeping in veg over the winter. I have popped them out of their 4x4 inch square pot, cut away an inch on each side of the square and from the bottom and filled the void with fresh soil. Worked great, they love it.