I would like to encourage your expressed interest in doing modeling to gain understanding.
Part of the oversimplification comes from citing Stephan-Boltzman equations and not understanding exactly to what they do and don't apply. In the climate change problem, this same difficulty arises.
Then, mixing in "personal experiences" which may not actually shed any light on the specific discussions, but these are sometimes given too much argumentative strength as is common, say - with eyewitness identification of rapists only to have DNA testing years later reveal that the semen did not come from the person identified by "eyewitness testimony" from one, two or three or more witnesses. There is a whole (but small) industry on reliability of personal experiences.
One can find limited function demo versions of finite element analysis codes online.
Some of these demo versions are said to allow 1000 nodes. Some of these analysis packages have mechanical and thermal modules.
Yes, there is certainly a percentage of the population that won't believe any computer model, and will believe what they interpret of their personal experience over and above anything that contradicts what they already believe.
In other words, there are some people to not bother trying to convince. I am very glad to be retired and not have to face those people.
We have long been bamboozled about the thermal characteristics of our outdoor gear, both by the outdoor industry, and also by the outdoor media, and by ourselves.
Look at the very long time it has taken to get a standard approach to rating sleeping bags, and then look at the holes that were left in the standard.
As you appear to well know, the lack of basic published analysis is stunning.
On the other hand, we can persist in living without the understanding that technology can provide, after all, we've gotten along "just fine" for a long time.
I have a "down and other insulation" database of about 80 Megabytes of downloaded materials, and ran out of interest and patience to read it all. It isn't like the subject of human garment insulation is some very recently discovered need, after all.
So, why is it so seemingly bad?