I have dabbled in real estate, but never heard of brrrr before now, and transparently never did much research outside of knowing that property ownership was a way to reduce my taxable income. 

You need to be weary of that and reduce liability as much as possible. 

Normally when a  property is advertised as "cash only" the property is in poor condition and/or the seller wants to reduce contingencies and opts for a cleaner transaction.

The down fall is a Heloc can "Never" be used as an asset or for PITI reserves required when buying a new Primary or investment property.A heloc can also cause major issues with credit and one slight hiccup or missed payment the bank or lender who is holding the Heloc can close or reduce your line of credit.

Consider starting with a few lower-cost flips with a smaller loan-to-value ratio to reduce financial strain.Market Research: Sacramento can be volatile, so I’d recommend keeping a pulse on local trends—particularly in the neighborhoods that have potential for growth but haven’t quite hit their peak yet.

This is because the main house often includes value drivers that ADUs do not, such as larger living spaces and more comprehensive amenities.

. - Consistent Payments: The rent portion covered by the housing program is guaranteed and paid on time, reducing the risk of late payments.- Large Tenant Pool: Housing programs often have waiting lists, so demand is high.

As in - we will not vote for your bill unless you include our other thing there.

Not only low-flow, the flushing mechanism reduces the likelihood of clogs.  

I'd say the logical paradigm in the question is a bit off.CRE includes everything from airports to golf courses to hospitals to campgrounds.So saying "residential versus commercial" is like saying "bacon versus plant life."