General

You broke both at 350 lbs? Either you were engaging in shenanigans to the highest degree, or you got some low-quality frames.

Im 400 now 😂 and getting bigger

Dont want to specifically quote but I hinted in the reply. Reinforedbeds a company in the uk. Give it a search and im sure you will find a specific company.

I've used a metal frame since I broke a flimsy twin bed as a teenager while vacationing at a lake cabin. I chose the bed I have for other reasons too, including aesthetic ones, but it's also held up well as I've continued to gain. I have noticed though, I can't cut corners on cheap mattresses. They flatten and develop indents in no time.

Hear here!

A bed is both a mattress and a frame at minimum [I would argue that there is considerable weight in aesthetic as well]

But sadly a well designed frame without an appropriate mattress is not going to hold up

Wife and I use a base mattress and a memory foam mattress with a topper, without an actual frame. The whole apparatus sits a smidge lower than a bed with a frame, but it’s most comfy for both of us. It absorbs our combined 500 or so pounds nicely ;-)