Hum, how to make a $13,000
Sapphire Rage into a nicely temp adjustable machine? Maybe, just maybe if you routed the exiting hose coming from the bypass valve through a remotely located electric (bout 4 amps) cooling fan/radiator, on it's back to water box, you might have the beginnings of taming the Rage for upholstery.
And, you might go further and install a variable temp control valve (they show installed in the flow diagram) and use that water circuit routed to a remote cooler back to the water box. You would still have a fail safe thermal relief valve in the water box dumping to the waste tank (though it might not see a lot of action with a bypass cooling system installed), and of course any fail safe temp sensor switches installed in the machine would be not be effected. With this set up to could set your wand or tile tool down for many minutes to fool around moving furniture or mess with detergents and/or spotting.
Or maybe
Sapphire has already thought of this and decided that's too much value for a $13k machine...