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.

If your money that you want passed down is in a ROTH or something your beneficiaries can wait 10 years for distribution to get them another 10 years of tax free growth. 

(To avoid months of probate and thousands if not $10’s of thousands of dollars in costs.)Hawaii is considered a "TOD deed state," meaning that residents can utilize Transfer on Death (TOD) deeds to designate beneficiaries who will inherit their property upon their death, allowing for a potential bypass of probate court proceedings.If she is already in memory care center.

All of the things you suggest are options to the beneficiaries. 

Sounds like this was a TIC setup which seems an unusual investment for an SDIRA (and problematic, from what I understand.)Aren't you the beneficiary of the inherited IRA? 

The title holding trust (land trust) is as its name implies simply for holding title, an estate planning trust (what I think you refer to as a personal residence trust) would be the beneficiary of the land trust.

However the event of default just gives the holder or beneficiary of the security interest the RIGHT to accelerate all payments and call the note due..

There’s a good chance that if lender finds out of property transfer via title records, insurance policy beneficiary, bank account submitting mortgage payments, they’ll assume that John  Smith formed a trust to own title and will not flag the  file for any action.  

I think if the end result is affordable housing people need to be invested in their own housing otherwise a good percentage of the beneficiaries of your program won't care.  

A better idea is to purchase it inside of a LandTrust, making your LLC a beneficiary of the trust.