As someone who did uber and lyft, let me tell you that these algorithm are exceptionally fine tuned to meet $/hr over long term driving. In my area, it is tuned to hit close to 20/hr ± 4 dollars/hr. You bet that on some trips uber is taking larger percentage vs other trips to meet this target. This is clearly how their system works to squeeze every dollar out of both drivers and clients.
Note: this is with OR without doing promotions and specials.
Those algorithms will try their best to get you out of profitable areas and stick you with low pay rides once you pass this 20/hr threshold. Especially if you are doing promotions, as they know that you will more than likely meet this target $/hr mark.
You could put a loop system that circulates the cold water from the pipes back through the heater for a set amount of time, then have it switch over to sending the water to the shower. The problem is that a set of pipes will need to be installed that can send the water back and may need a custom solution on switching from circulating to dispensing. In the long run, it would be cheaper, but it would take a fair amount of time to pay itself back. The positive is that it is cheaper than installing electric heater on every water outlet but more expensive for just one outlet.
As you said, the pipes are not easily accessible. You may need to just live with it or suck it up and pay the professionals to install either the whole house water scavanging system for every hot water tap to be hot or just an electric water heater for just the shower. Depends on how much you want to save water vs. how much cash you can throw at this problem.
There are TOO MANY procedures/fees/tax/unsafe ways to lose everything you have or be in a position where you will never be able to live without constantly being demanded to provide more work/cash/time.
All of this is true,
instead of happening in schools for the advancement of knowledge,
it is happening in corporations for profits and egotistical power trips.
Subsidize based on type of transportation used? Public transit is mostly subsidized, and private transportation is the least subsidized. This would make employers seek out poorer people.