If TMX was single layer it would be the single pictorial Kodak product having a single layer.
All color films are multi layer, many sporting 9 sensitive layers. Ektachome... TMY, TMZ, TX and TXP are also multi layer. Why TMX has to be single layer ?
Let me use your words: "Again, you have very limited understanding of Photo System Engineering. You have repetitiously failed to disprove that much."
First you don't realize that the extra layer is an absolutely must to yield that insane linearity in the highlights:
1) The separated cubic layer efficiently prevents most of the infectious development from high sensitive T-Grains to the slow cubic blocks, preventing an early shouldering.
Don't tell me you were not aware.
2) Placing the slow emulsion in the back makes it even slower from the casted shadows, which favors linearity in the extreme highlights, and this also favors linearity in the shadows because no low speed cubic blocks are casting shadows on the fast crystals.
3) If the cubic and T were blended then horizontal alignment of the T crystals would be lost, making the T emulsion less sensitive for the same silver amount and from the same grain (clumps) size.
Kodak engineers, with great effort, refined all the physics to place T crystals horizontal to catch well light and now you want to place all the T grains in arbitrary directions. Quite funny
Man, look, T emulsions are not much compatible with single layer coating.
Still, nothing is imposible, so just bring a reliable evidence of your weird statement, if TMX is the only film coated in a single sensitive layer this would stated somewhere, isn't it ?
To me, single doubt is Double-X, still sold for motion pictures.