It does not matter what set up you have as long as the pump does not stop at any point when the heater is working.
The spring controller, 3 button with cal or auto cal will need to be set manually to 99 so that the PRV activates before the controller cuts power to the pump
A very good condition battery is a must , mine is a 105 amp Numax , it gets fully charged after every single day without fail.
My pump shurflo 5.2 LPM is set to about 2 LPM , this and the heater draws about 5 amps per hour , my usual 6 hour day pulls about 30 amps in total 30% of battery capacity , if you are more of an 8 hour day merchant then a 120 amp battery is more suited as to not pull the battery down so much each day