i'm not a tire expert but i can tell you this: i run dunlop 606's on my dr650 in nicaragua and although i hate riding road, at times its inevitable. i'm a big fat bastard myself and have never worried about the tires overheating.
keep your rubber properly inflated and they'll be fine. one more thing, belize isn't famous for having much super slab and there are few places in that country you will be able to get up to and maintain high speeds for long enough to make a difference.
'08 DR650, '07 DL1000
"And anyways, if they don't have motorcycles in heaven, I'd rather go to hell. I'm pretty sure they will have loads of them there." (deelip, 2016)