Shurflo pumps are rated at several litres per minute. your system will maintain most of this pressure unless the combined rating of your jets exceeds the max flow rating of the pump.
Of course by incresing the flow through the water system and therefore the inline heater ( If you use one ) the water will spend less time being heated and be cooler at the wand.
When I used a portabe, I ran it with smaller jets to maximize the benefit of the heater. I found that this plus more than made up for the downside of reducing the flushing capacity of the machine