Pruning just introduces holes that pests can enter (the stems are hollow). I'd wrap them around or if you can put in a trellis or wire fence or something they can climb, then let them do that. Or prop them up over tomato cages, etc.
My zucchini are growing huge this year, usually they have a few fruits and perish. Who knew?
Some are a bit crowded, and I've simply staked the area with tomato cages and old sign wires to kind of give air to the acorn squash too close to the old huge zucchini.
My garden regularly straggles way past the edges of the garden out over the driveway on both sides. It begins to get a little narrow by fall! If you have space where it can sprawl, don't worry if it is outside the lines.