Does anyone have suggestions for mushy/soft food ideas for the grill?

Things that are mushy won't really grill, they'll just seep between the grates. You could grill something, then turn it into a mushy. You can turn anything into a mushy with a powerful blender and some milk.

I don't feel like I've really given you any information, maybe I'm misunderstanding what you're asking by grilled mushies?

ETA: I have grilled tofu, now that I think about it. But IMO it's better in a pan.

OMG get a grill basket.. You can do veggies the longer the musshier and peaches, squash, mushrooms,