It was easy and clear with wire object where I just need to dial the parameters under elasticity tab, but this vellum hair thingy simply won't become “erectile” no matter how I tweak it.

Try lowering the curve density, reducing the mass, and increasing the number of constraint iterations.

Generally, the number of required iterations increases with the square of the number of points per curve. The apparent mass of the curve also increases with the square of the number of points. Reducing mass increases the apparent stiffness of the curve.

https://forums.odforce.net/topic/41015-vellums-bend-stiffness-control/?tab=comments#comment-196944 [forums.odforce.net]

see the 2nd file for easy comparison.

thanks very much guys