You don't have to do anything with the money and there's no time limits or anything.2.

You have a limit if it is an ADU.

Maybe its just a blip, but I'm hopeful that we'll see population increase in the city limits sometime in the next few years.https://www.cleveland.com/news/2024/05/clevelands-population...  

If I understand correctly your siblings goals are to sell their rental properties, use the funds to purchase a primary residence they'll eventually move into, and limit their tax liability correct?

However, prices for a comparable 5-bedroom home in Washington are significantly higher, likely around $1.5M or more, which would mean taking on a new 30-year mortgage with 6+% interest rate and limiting new investment opportunities.2.

Credit is a factor as bad credit may limit options, or may have the lender require you to put 10 or 20 years of taxes and insurance into escrow. 

.- Many of these HCOL areas also have strict limitations on AirBnB or short-term rentals... that do not apply to owner-occupants - thus allowing for extreme cashflow potential for house-hackers.

Control and Flexibility: With an SDIRA, you're not limited to stocks, bonds, or mutual funds.

An example of that is tenant must pay for additional electric over flat fee / flat limit since now there is 2 occupants in the home instead of originally one.

They view each loan individually and have been lending to me even though I only work my W-2 on a limited part time basis.