The standard Detail / Sharpening and Presence / Dehaze sliders work with the [Alt] key to display the mask being applied. I find this extremely helpful. Why don't the Texture and Clarity controls also offer the quick mask view via the [Alt] key? Is the scale too small to be viewable? Is there a technical limitation or is this something which can be added in a future update. (I'm using LRC 11.5 in Windows)
Texture and Clarity do not apply a mask, so the answer is probably that an Alt-view showing the image in B&W doesn't really give you a better view of what is going on than a normal view. In fact, it may even be worse and give you the wrong impression.