In this case, would the IRS reject a prior return's use of a DIY if a full engineered study supports or exceeds the deductions that it reported?  

I think if the investor has had bad experiences prior, then Yes, a call from any sponsor comes with a cloud of anxiety on what the call is about.

Most, if not all screening tools do not include a comprehensive rental screening with a renters prior rental rating like Mayistay. 

This was my first property, I've owned it for about 3.5 years, and "started" in RE about 4 years ago (all stock market investing prior).

I have an applicant who says she lived in the Dominican Republic prior to the 2 years she's been at her current address.

Quote from @Jay Hinrichs: Quote from @Engelo Rumora: @David KanarekI don't think I have ever seen better investigative research than this.Hat's off to you and sorry for your troubles and everyone else's.Please don't investigate me haha Engelo this is all the Due diligence that should have been done prior to investing its fine after the fact but that's not going to get their money back..

And even here, you still need to be "active" to research who you are lending your $$ to, and due diligence on the deal itself prior to investing your money.

Thus a DIL executed prior to default creates title insurance issues as you can't satisfy the underwriters' checklist -- prior default, comparison of value vs. amount owed, a negotiated DIL agreement, etc. 

Do you provide move in and move out reports How many pictures do you take of the property prior to tenant moves in and after the tenant moves outDo you get weekly reports when the property is vacant what prospective tenants are saying about your homeDo you provide monthly newsletters to your tenantsDo you hold investor education classes to help me become a better investorDo you have single point portfolio based management services?

Sounds like you've navigated the environment by having an overall lower risk exposure prior the market adjustment.