interesting, i had not seen that before.
this is what i had seen:
https://powerdrivendiesel.com/product/afc-live-gauge/
ultimately however, both are only doing one thing. they limit the max travel of the AFC and therefor limit the max fueling available. one physically moves the end stop, one interrupts the boost reference and limits the max PSI to the pump. one of the first steps in tuning a p-pump is to set the AFC spring/plate so that it achieves desired max travel (based on your possible fueling) at your max boost. limiting the psi will limit the travel just like putting in a physical stop.
so for $30 i bought a precision parker air pressure regulator with air blead and will stick it in-line with the boost reference. i'll also copy the AFC-Live guys and have a bypass valve switch. unfortunately it's not really a linear or proportional tuning reduction, just turns off the stupid zone. the AFC-Live also includes an orifice valve though, so you do have some control over how quickly the max psi you set is shown to the pump. combined these help make a 1000hp truck more street-able by giving you a simulated better throttle resolution.
the best solution would be to have variable in-cab control over the AFC spring rate, but i've never seen that. tune the truck right for "race mode" then use something to limit that for "street mode"