I have a Hagie sprayer that had a Raven 460. I put in an Ag Leader Versa. Doing that I lost the manual switch to operate pump. I want a way to turn on pump without being in field over land that the controller thinks needs to be sprayed. Priming, agitation, Can I put a DC motor control like this and have a dpdt switch to change power source for valve?

https://www.ebay.com/itm/DC-10-60V-20A-Motor-Speed-Controller-Pulse-Width-Modulator-PWM-Shell-Motor-USA/352683490152?epid=506609832&_trkparms=ispr%3D1&hash=item521d92fb68:g:d6YAAOSw3tBc9iC2&enc=AQADAAAB4KX%2FKt4E1xf3SDqEdBclaYYppa8QpnAEbvYsP2bUgCq1YuyR3ZwT6USmONLcmda5umgwtoAcQ8HBWQDpLbvbUaY0i0P0U4DU7EVImgPqfCgym89ULkRTrfjb%2BRUaL1Gk5wXphgte49yCe5qY7kxIqd6jABO6Fw0srMNc1WNF05lT%2BCuaSGAM%2BDbdyneuvT8SI7XodDjbHxRy2om3FPXKkTY%2FB3f0mgbfYVTpBPEV76LjknAQVclybuldaG%2BHoqj%2BXKe3n6ufkMrTUyWPFv6zcWRSLLi%2Fi6hgKhZkvGw9HqpKXOn%2FvcZAOLu1D7meHpFXMZoKJ%2BLrtd45rZWOnIUoPJHx8oHERMXPLOCrPBNSwN4i6UneiGiBE%2BHBzDztzBNFlgqVGDONVgFDrUb8udV55Vmi5%2FJqAGkQpEbM8DaLqGFS2bGm488EzE53nPDlN5Pac5qB%2F0ZzCgTJXoUZ1HCFpnEpW0mljIMKOWhl9Rw3xax2hXXrDep3JfAGK7sMn9gCWB4qXRplSGX05kGn%2BuRP%2BIgC9jAqRGBBEzx9%2BMBdmYf4JAZUtVeuE3Arf4ve8q5Pfl1g6ybADNNZ9DcXZmttPVOq08IT0luUx%2FVhx4YZG44FK8Q%2FB2p5ggNw7r1ENGZpyQ%3D%3D&checksum=3526834901525a6750ed252945b4a82c1deb0ce2a9ea

The PWM power is close to impossible to measure easily, isn't it?