Of course, the eventual plan is to refinance the home as soon as possible through a traditional mortgage, to reduce the excessive amount of costs with high interest rates from hml.

But shoveling all their excess cashflow into software by hurrying to automate their first property is bad business practice.

However, it also depends what exactly those expenses are, e.g. unnecessary payroll would be something you should be able to correct (and if you lower it, you increase the value of the Facility); high flood insurance or excessive property taxes are what they are and typically cannot be reduced, very well throwing off the "industry standard".Typically we recommend buying a Facility as it is currently performing (past 12 months) and use a pro forma only for where you can realistically take it. 

Just keep in mind, whatever they do not have to pay for they will use to excess and you will have to pay in the long run.

As for the ‘excessive’ family gatherings at your house: you have no control over it.

I sometimes drive in excess of the speed limit.

Then that should be clearly defined in your lease along with the cost of excess bandwidth. 

Remember if your rental is creating a profit in excess of depreciation, paying some more income tax is a good problem.

There are two possibilities going on here and you didn't specify which one you're dealing with. 1: they work with a company that installs the panels, gives them free solar energy, and then sells the excess.

Essentially take all the excess cashflow from your investments and put all of it towards one mortgage until it is paid off.