No, it hasn't.
One of the early physiologist (I think Haldane) excised veins and explitly measured gas tension in blood returning from differnet tissues. It is a bit of an abstraction since of course a given tissue can have subcomponets with different gas solubilities. For example bubble formation in the spinal cord is observed primarily in lipid rich tissue. So if you want to divy things up at the level the model fails. Also "12 minite tissue" can be serveral disconnected sites across the body so are those all the same tissue? This is a problem of usage and not of physiology. It is a useful abstraction because it works.
Yes, a given tissue can have various sub-components with different gas solubilities.
Furthermore, I do understand that when people talk about a "tissue" represented by a theoretical tissue compartment they are referring to several disconnected sites throughout the body. I don't have an issue with that.
I do recall a study of gas tension measurements on
in vitro nervous system tissue (spinal cord), but this hardly approximates what occurs
in vivo in a human during/after a dive. Anyone who does work with
ex vivo nervous system tissue understands that the tissue is compromised as soon as it is removed from the body and, consequently, the time for studying it is finite. This window for study varies, depending on many different factors. Moreover, I'm not sure how one would use this data in making comparisons to other "tissues" (bone, fat, muscle). Yet another complicating issue is how blood shifts, which occur during/after exercise, affect nitrogen loading and off-gassing.
The abstraction of which you speak oversimplifies things and is misleading at best.