OK, Time to clear up the GMC/TZE things. (Look at the pic in the sigfile.)
There is no tag axle. The statement that the rear are in tandem as opposed to dual is correct, but by definition (according SAE) that is a single rear axle as the designed (some have changed) only has the single suspension for the tandem wheels. The ride in the back is so nice that when needed, we can sleep the off watch crew. We tried that in a Class C and that is all I will say.
GM dumped all of that business in 1978 and have not looked back, so don't ask them. The well established community of owners knows way more about it now than GM Truck and Coach ever did....
And No, what you do at the rear has no effect of the load on the front tires.
Could "Chrysler" pick it up and run with it? Sure they could, and they would be smart (IMHO) to do so. If/when they do, they would be smart to look at some of the re-engineering that has been done in the community. But, from the contacts I still have with that ex-employer, they are distinctly not interested. They dropped the whole RV effort when they shut down the big block line on Mound Road. That was part of the loan guarantee deal with the government.
Matt