People usually construct a wire trellis system involves a heavy gauge wire and sinking 4x4 posts cattle panels won’t cut it as you have found out

What annual quantity of berries is your goal? That will determine how aggressively you need to top-prune and/or limit the number of primocanes per clump.

My question would be how to keep them from spreading. I had a Kiowa blackberry in a pot which not only threw out enormous canes but sent its roots out through the drain hole and popped up 2, 3, and 5 feet away from the original. I dug it out and gave it away early spring, but new growth is still popping up in those outlying areas.

Getting a mower out in between rows will keep them at bay

I use cattle panel for Chester and Triple Crown and it works really well. I bent a piece of panel into a U shape so it is about 3 ft wide and 6 ft tall. I placed this U "up side down" over each plant and let the canes grow up and through the panel. I secured the upside down U with some T-bar just to be safe but I don't know if it is needed. It is sturdy enough that it can support my weight if I hang from them "I am over 200 lbs". Each plant takes up at least a 6x6 ft square and is about 7 ft tall were the canes bend over. I get quite a few berries off each one easily 20 lbs or more.

^^ Hmmm...I could see that working. We just secured the cattle panels vertically.