Estimate passengers number option issue

[MARENOSTRUM]

GSX level 2 is great .
Till now I am seeing passengers and customizing all stuff properly...
...with the exception of the estimate passengers number option.

if UNCHECKED I am not asked to write/say the pax numbers.

I am using PMDG NGX/ MajesticQ400.
I would like to fasten the boarding accordingly with my SOP not by haveing them too dense (using P3D 3.4 32bit) but setting a smaller number.

Is the number taken by the PMDG FMC (it does not seem)?
Should I have to see a pop up to write the number of PAX?

Thank you.

[virtuali]

if UNCHECKED I am not asked to write/say the pax numbers.

Yes, you will asked to, but try a Couatl restart after you set it, because it might be read only at the start of the program. After that, is saved, of course.