Valid concept
I have a bit bulkier set up - a wing lynch automated film rolls in a tube processor. It keeps the chemistry at 102F (or wheatever you have tweaked each separate tank to) on it's own, but relies on an incoming water supply to temper the tube itself, and for wash cycles.
I would go broke if I had to keep the hot water running on for the length of time the thing wants me to, even at a trickle, so I built a work around.
I had an unused small roller b&w processor, and I scavenged the heater, thermostat and pump out of it. Along with a good sized jug to act as a reservoir, and after a bit of water and drain reconnections, I now have a recirculating temperature controlled water jacket for the processing trough. Works like a charm.
For c-41 for many years I procesed in stainless steel spirals and tanks that were tempered, along with the chemistry, by a fish tank heater and pump running in a 10 litre lunchmate sized cooler.