To be honest I want to house them together because its easier to deal with (physically and financially) one big enclosure as oppose to two slightly smaller enclosures. If I wanted to house two female burms in one 8'x3'x24'' cage it would be easier than one burm per 6'x3'x24'' cage.
As for thermoregulating, if there's a big enough temperature gradient in the cage, how would it be a problem for the snakes to accomplish this? Sexing wouldnt be an issue either because I get my burms screened and sexed by a local vet along with me popping their vent for gender.
It seems like proper husbandry of the snakes would keep a lot of these problems from arising. Please dont take this as me dismissing your post, but maybe it wouldnt be as bad as you think it would be as long as proper husbandry is practiced.
Thanks.