Thinking along these lines last night and the night before.
Been working in Derby, on a store, drain jetting the car park slot drains, 1000 metres and a heckuva lot of tidying up, a great deal of switching from jetting to pressure washing.
The Hot & Mighty has to be switched off, the pressure released and then switched on again, every time we switched between the two.
On my other jetter there is a slider on the side of the engine that takes the pressure off the hose and makes it easier to mess around.
What about the unloader to full return to tank!!!!?
It must be a really easy fix to fit something, that kills the flow, all of my lances are quick release on the nozzle end, similar lines!!
Rob