Thanks for that @SimonC
Here is my default preference for NOBDII:
Collar Band: Light Unfused Lining
Collar Points: Light Unfused Lining
I’ve used this combo for all my NOBDII shirts including a white twill for business suits. The thickness (or thinness) of the shirt fabric more or less plays a factor into how robust the collar is, but I’ve found the lining setup above to be a fine medium for both ties and tie less with a sportcoat. No flaccid collars over here.
Do you happen to have link to that fabric?