The Shapeoko machines and control is very different than what you have, and yes they are very used to using PWM for there spindle speed control with one problem, all the machines they sell do not use a VFD Drive or a 3 phase AC Spindle motor most are using a Dewalt Router and other brands, which you can control the speed with a PWM signal, they can also change there PWM signal to look like a Analog signal with a low pass filter which some of them have done
It's good to know that this can work but I would not advise users to use this as there are very few VFD Drive that have a PWM speed control option
Again more misunderstanding of how your VFD Drive works PD005 PD011 these are fixed Parameters and not related in anyway to PD072 and PD073 these 2 and others in the PD070 window are only related to Remote Speed Control and can be any numbers you want to make them within there range, and are normally set for your motor spec's