Calculator parameters for SPP

[Birrofilo]

Hallo.
I very much appreciate the calculators in the parent site.
I have bought spiral prismatic packing (SPP) for my column.
In this calculator: https://homedistiller.org/calcs/reflux_calc one cannot select SPP as packing (there are options for Raschig rings, SS wool, marbles) but it is possible to insert the specific value for a different kind of packing.

% Fractional Voids in Dry Packing
Diameter of Packing
Surface Area of Packing
Critical Surface Tension

Does anybody have good "guesstimates" for these parameters?

The site where I bought the packing states an HETP of 2 cm.

As an alternative to inserting the unknown values, could I just calculate the HETP that I will have in my column (let's say I want to use 7 theoretical plates) and tinker with the values of a SS wool column until I obtain the correct HETP value?
That presupposes that HETP values are the only things that matter ultimately, so if I trust the 2 cm HETP value given by the seller, I should use the calculator effectively. Is that right?

Thanks for any support
Fabrizio