I would think it'd be pretty simple to calculate his actual rent income based on the properties current conditions and explain that at best, the tenants in place stay for years to come, he continues doing the bare minimum, and his highest predicted income is x dollars, barring any emergency spending to keep the tenants happy.

Don't know anything about them but per my calculations they are taking 27.2% of the capital appreciation on the New Braunfels deal at the end per their projections which seem optimistic in this oversupplied environment, (Austin MSA with largest new multi-family projects coming out this year in the country ,8% of total existing stock and already seeing rent rate declines of near 10%in the city so far) and they are taking a big chunk of the monthly cash on cash as the preferred payouts for their 3 different classes are well below the projected cash on cash total.

I recognize that my expected return is different than many of the members of BP, but the most successful of investors do not consider a loan on one asset to purchase another asset (whether it is stock via margin, home equity via HELOC, borrowing from 401K, etc.) to be the same as leveraging the value of the financed asset in the financing. 

I'm selling my apartment furniture in Tucson, AZ from my airbnb for a 2 bedroom / 2 bath, this includes a full living room, bar stools for the kitchen, a fully stocked kitchen, and laundry room.

Could have done better in the stock market with no work.  

Fannie Mae predicts a gradual increase in sales transactions and home listings this year.Indeed, NAR Chief Economist Lawrence Yun notes there are nearly 6 million more jobs compared to pre-COVID highs.

That database is quite large - and its ability to predict pricing is getting more fine-tuned and accurate every day. 

The HELOC for the eventuality that you find problems that are more expensive than you predicted, and use as an emergency fund.

What if you don't like real estate in general and prefer stocks?

nobody knows because stock market is at all time high.In other word, rather than capital call, it's best to admit defeat especially if your DSCR is less than 0.90.