IME it's not the techflex sheathing itself which makes the cable bundle less flexible, its that there are multiple cables bundled together within the sheathing. In other words, if you were to techflex a single cable, it would not be significantly less flexible unless it was really thin to begin with.
However, most tapers are not using techflex to protect a single cable. Instead, they are using it to bundle two or more separate cables together to create a single run. In that case you need to weigh the trade-off between having a single less-flexible bundle versus multiple more-flexible cables.
The specific application and strain-relief strategy for the connections are key elements in whether "techflexing" is suitable or not. Also, keep in mind that there are many different styles of techflex, some is more flexible than others, some expands more than, some has a different feel or "hand" than others, etc. And keep in mind that it needs to be the appropriate diameter, as its range of expansion and contraction is limited.
I don't particularly like the taped or heat-shrunk every few feet method of bundling because that doesn't bend as cleanly, can easily hang or snag on things, and just doesn't work well for me. I'd rather use single cables that are simply all tied off together with velcro ties at a couple points along the stand. But if I am going to bundle, I prefer texflex or the equivalent.
Example- I use standard techflex to bundle six thin coaxial microphone cables into a single run. Since the cables are thin and very flexible to begin with, the resulting bundle isn't overly stiff, although it is fatter and stiffer than a single standard XLR mic cable. Fatter mic cables within the bundle will sometimes cross or twist within the bundle making lumps and non-smooth bends and coils. I typically carry the bundle coiled in about a foot diameter loop, but it can make a bend in about half that diameter. This bundling makes the rig far more streamlined and clean, and makes for easier to manage setup, breakdown, and transport. I would not want to run 6 seperate mic cables from my stand to the bag, have to coil and uncoil each one, any deal with the inevitable if occasional rats-nest.