Dual PRO as opposed to Dualhead extruder uses single nozzle. According to that, for saving calibration parameters for Dualhead extruder it is possible to add the following lines to config file:
extruder.x_dual_offset -11.25 # x offset for old design dualhead, by default -11.25
extruder.y_dual_offset 0 # y offset for old design dualhead, by default 0
which parameters are related with lines
extruder.hotend2.x_offset -11.25 # x offset from first tool in mm
extruder.hotend2.y_offset 0 # y offset from first tool in mm
which are parameters of calibration of dualhead extruder. To make switching between Dual PRO and Dualhead extruders possible without loosing this parameters please copy parameters form lines (2) to lines (1) and reset the printer.