Wow! That is some garden. I don't know where you live but you must get a lot of rain and it must be very warm since your plants are so big. I have to use drip irrigation and it works but my garden isn't as far along. My squash and cantaloupe and pumpkin are just getting their second leaves...
I still like to see other peoples gardens whether they square foot garden or not. Screen is a good idea on keeping the potting mix in the pots. I use rocks or bits of aviary wire for mine but the screen would keep out the critters. The rabbits can't get to mine anymore as I've fenced them out...
I'll take photos of my garden whenever this blasted wind dies down. Large containers do well for vegetables. Use potting mix, not potting soil (there is a difference) instead of regular garden soil and you should do well.
I have been using raised beds for years but didn't put the grids in. They work very well and since I live in the desert and the soil really isn't anything except decomposed granite I can have decent soil for growing. I have four raised beds with tomatoes, green beans, cucumbers, beets...