Hi MAC,
While latex would be more durable than even a high quality polyfoam support core … the deeper support layers of a mattress aren’t generally the weakest link of a mattress so while it could add some additional longevity (especially since you are in a higher weight range that would be compressing the deeper layers more than someone that was in a lower weight range) … the benefits of a latex support core would also include greater point elasticity (the ability of a material to contour to the shape of your body), the more resilient or springy “feel” of latex compared to polyfoam which some people may prefer, and the higher compression modulus and more “supportive” nature of latex (how quickly a material becomes firmer with deeper compression) and how the different properties of latex vs polyfoam change the “feel” and performance of the mattress in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences).
There is also more about the many variables that can affect the durability and useful life of a mattress relative to different people in post #4 here and the posts it links to.
Phoenix