All your points are valid, but I wanted to clear a few things
You have the right to it as a landlord/owner, but maybe not the tenant
You pay in most counties in Florida for water in (water bill), and water out (sewer tax), so rainwater systems have no cost to the system since rainwater cannot be piped into a home without it being taxed as a home improvement. Most places in the USA, the gray water installation for the home, not the garden, has to be inspected and your taxes are adjusted accordingly, if you are subject to the sewer tax is another thing IDK
b) Growing your own food
That's completely off topic, since you are not responsible to the producer
If the leases are in your own home without any feed to the system, then you can install, but you cannot get any tax benefit (state wide) since you are not the owner of the system.
Having access to over 100000 sqft of usable sun facing roof space spread over multiple clients' homes, I spent a while researching this, and ran into the same problem. Leasing platform or having some 3rd party agreement with a producer will not provide a return of any sort on the invested capital. So the only solution I found was to tell my clients to get them installed, make sure they have net metering and talk to the accountant and get whatever tax break they could find. No real money is being made, but since they are snowbirds, they have a huge credit for the winter.
The problem is that the energy created, is fed into the power lines at retail, which the truth, it should be fed into the system at 50% or less than retail. and what the leasing people are trying to do is force the producers (power companies) to buy retail...
Now imagine 100000 sqft should generate about 800 to 1200 KW at peak, that's got to help cut down on carbon, which I am happy to say I've done a little bit too help.