I'm pretty sure I can do a long-term fix on the futon frame. Bought a piece of metal the same width as the broken piece. I'll cut it to size, borrow a decent drill, buy some heavy-duty bits and some wood screws, squirt glue in the cracks and clamp it, then drill some pilot holes in strategic spots and attach the piece of metal. And as an added measure, I'll use some zip ties for added strength.

I have my eye on a solid maple frame made here in Maine, just need to save up for it.