All of my machines have dual hex-core Xeons (HyperThreaded), hence 24 threads. All are either Win7Pro or Win7Ultimate. So, the 32 limit shown in the screenshot doesn't make sense to me, unless it's a coded limit. Poser does automatically select the correct number of threads by default (24, in my case).

Could someone with, say, a core i7 quad-core post what their render thread limit is?

Could one of the devs give a definitive answer? If this is a hard-coded limit within Poser, do the devs intend to increase it for P12?

Is the 64-thread limit peculiar to Win7, or does it also apply to Win10?

Poser 12, in feet.  

OSes:  Win7Prox64, Win7Ultx64

Silo Pro 2.5.6 64bit, Vue Infinite 2014.7, Genetica 4.0 Studio, UV Mapper Pro, UV Layout Pro, PhotoImpact X3, GIF Animator 5