The reasoning isn’t at all what I thought. It’s less about accommodation of the body and more to do with the heat generation. Fat creates 20,000 BTU of heat compared to muscle around 1,000 BTU. So it is actually dangerous and a fire hazard to cremate obese people.

They mostly charge more because it’s slower though. Most bodies can be cremated in an hour and a half to three hours, meaning that multiple cremations can take place in a day. Whereas obese cremations may consume most of the day. So you’re talking 3-4 hours of cremation for a morbidly obese person. That’s not to mention likely needing multiple personnel for transporting the body or the slow cooldown of the remains. And then having to be careful of a fire hazard.