Hi sweatdog,
In most cases a latex mattress is designed to be used on a firm non flexing foundation rather than a support system that flexes (like a box spring) although there are a few exceptions (generally thinner mattresses) where a manufacturer has designed the mattress to be used as part of a sleeping system that includes a flexible box spring (with springs inside it) or flexible slats underneath the mattress.
foundation post hereThere is more about which types of foundation or box spring does best with different types of mattresses in the and the two links in the second paragraph.
I would always check with a manufacturer to make sure that any foundation, box spring, of support system that you are using meets their warranty criteria but in most cases you would be better off with a rigid non flexing support system with a latex mattress.
You could also use a sheet of plywood on top of your box spring although that also wouldn’t be an ideal choice (see post #10 here).
Phoenix