PenFed Credit Union offers these HELOCs at 80% or less combined-loan-to-value, another that I know has these type of HELOCs is Quorum.

There are still 2 55 gallon drums with some combination of oil and other fluids. 

That umbrella is also per property and not combined.

It's say it's more a combination of the threshold you and your potential clients can accept.

Potentially this site itself is in on the scam, because the reporting function there doesn't work.   

I love the idea of house hacking, but friends and business can be a volatile combination.

Agree that Fund Managers and Intermediaries make money off of those but that's just a nature of their business - like @Mike Dymski mentioned there are companies that charge less and it's the employer's responsibility towards their employees to find the best possible combination that benefits them both.

Is there any specific commercial loan product that combines with a rehab loan?

Could it be from the shower itself combined with the weight of the person? 

So it functions as a 2 bedroom in their case and they use the railroaded room as an office area.