What is the minimum amount of profitability acceptable at a $60 million loan volume4.

That is why I say I don't think it is a good plan (for my lead generation standards) BUT you will more than likely get lucky and snag one deal... or 2

Commercial Revenue Generating properties like office buildings, apartment buildings, retail centers, etc (banks call it "CRE" lending) are typically evaluated from their net operating income, not gross.

Also, for me 30+ bookings tend to be less profitable even though there are less vacancies.  

However, if you are profiting over 6 figures, the property might be too expensive to live in order to truly house hack.

Unfortunately I was not able to put much away for retirement most of my life so I was thinking about attempting to buy 4 rental units over the next 4 years with the hopes of building up something that could generate income in 5 to 7 years to supplement my retirement at 68.

Generational Wealth: If your SDIRA invests in real estate, those assets can pass to your heirs, benefiting from the step-up in basis (outside the SDIRA) or continued tax-advantaged growth if inherited in a beneficiary IRA.

Here are a few strategies to consider for funding a down payment:Partnering: Like Gregory mentioned, finding a partner who can contribute to the down payment in exchange for equity or a profit share is a solid option.HELOC or Cash-Out Refi: If you have equity in your home or another property, a home equity line of credit (HELOC) or cash-out refinance can provide the funds you need.Private Money: Reach out to friends, family, or private investors who may be interested in lending you the down payment with a promissory note.Seller Second: In some cases, the seller might agree to finance a portion of the down payment as a second mortgage.Live Frugally and Save: It takes time, but reducing expenses and setting aside funds from your income is a tried-and-true method.The right approach depends on your situation and deal structure, but a mix of creativity and resourcefulness can go a long way.

agree .. other wise its just the bottom feeders looking to take his equity from him  with couching it as a rescue.. his best bet it to sell if its owner occ the profit is tax free .. regroup and start over.. 

. $20,000 profit after realtor commission.