I agree with you. I have all my vents taped off and pump a lot of heat into the bed to get the temps up. a regulated heater is a better option. You do need to stay on the cool side of the glass transition temp though. otherwise you may get some sag in the prints. I thought Stratasys has a patent on the heated chamber which is why the market stays clear of that feature.

Interesting to see someone talk about glass transition temps in the printing world. Obviously you have had some education on the subject. I attended Akron U for their plastics program. Usually we only worry about those things in failure mode analysis and when specifying materials based on application. I would welcome you to write a post up on it if you have the time.