I don’t believe there is but double check on qualifying as a real estate professional with your CPA as it’s really tough to qualify with W2 income, you need to meet the following that eliminates most taxpayers with W2 incometwo quantitative tests of Sec. 469(c)(7)(B):Do the hours represent more than one-half of the total personal service hours the taxpayer performed during the year in all trades or businesses?

@Jeff BrownEveryone's tax situation is different.There are millions of taxpayers with real estate.Will you have people with similar experiences as you - Yes.Will you have people with different experiences as you - Yes.You should have a talk with your accountant on why your tax return is different now than in the past.

You and your Solo 401(k) are distinct taxpayers in the eyes of the IRS,Trump tax reform has precluded the "netting" of income/loss from separate business activities that are subject to UBIT.If your objective relates to #3 (above), there would be benefit derived from a cost seg study - assuming the Mobile Home Park investment is truly subject to UBIT.    

I thought one of the basic filters the IRS ran was to check to see if the taxpayer's aggregate W-2 and 1099's reconciled with their records?

Taking a lower price with Owner Financing would help the total amount collected and spreads out their income which might make less in tax payments. 

Such lienholders must pay all of the normal charges that any taxpayer would have to pay in order to redeem.

Considering many people are renting basements illegaly, which they have to in order to afford the tax payment, it's not a sustainable path for growth in my opinion.

If for whatever reason UBIT is paid directly by the taxpayer, the amount paid is considered a contribution to the IRA.Follow up question: Is there any difference in how the UDFI will apply for these: 1) SD IRA 2) SEP-IRA 3) Solo 401K 4) SD IRA (operated as an LLC) so this one is confusing...

If taxpayer pays taxes on the 29th of March then he doesn't get charged anything over.

An LLC that is single member and chooses to file taxes as a sole proprietor and does not file it's own tax return is "disregarded" by the IRS and the tax return where the properties are reported is seen as the tax payer.