Form 8990 for Dummies

Looking for help from some of the more knowledgable members here, like @nexchap and others.

I feel a bit stupid in admitting this, but I have wrestled with Form 8990 for a while ... and I have gotten to a place where I think I understand it, but I would like to confirm that my understanding is correct.

Background: I am an investor in a PTP, which is where my Form 1065 K-1 Box 13K item comes from.  No other business interest expense at all; only the items reported by the PTP.

As I understand it, because I am a small business taxpayer - meeting the gross receipts test of less than an average of $25 million over the last three years, I am not subject to section 163(j) - and thus I do not have to complete Part I of Form 8990 - but I do have to file Form 8990 to track the excess business interest expense.  So, I only have to complete Schedule A (lines 43-44) for this purpose. So far, so good (I think).

Now, as the PTP reports current year excess taxable income or excess business interest income (Schedule A, lines 43f and 43g), this will move this EBIE to the "treated as paid or accrued" category (Schedule A, line 43h).  I understand that; my real question is, what happens next?

As I understand it - but the IRS doesn't really come out and say this directly anywhere in the Form 8990 instructions or documentation - once this EBIE hits line 43h, it joins the rest of the accumulated losses for that specific PTP, subject to the at-risk and passive activity limitations.  But, the IRS wants a reconciliation of these Schedule A, lines 43f-h amounts before the EBIE in 43h is "released" in this fashion (my term, not the IRS's). For "small business taxpayers" who are only PTP investors, this seems like a large exercise in futility, although I understand how section 163(j) makes the EBIE different from other general PTP losses and expenses.

I should note that the IRS points to this outcome in the Form 1065 Schedule K-1 instructions, in the specific instructions for Box 13, code K: 

"Code K. Excess business interest expense. If the partnership reports excess business interest expense to the partner, the partner is required to file Form 8990. See the Instructions for Form 8990 for additional information.

For tax years beginning after 2017, the partner’s basis in its partnership interest at the end of the tax year is reduced (but not below zero) by the amount of excess business interest allocated to the partner for the tax year, even if the partner is not allowed a deduction for the allocated excess business interest in the year of the basis reduction. If the partner disposes of a partnership interest in which the basis has been reduced before all of the allocated excess business interest was used, the partner increases its basis immediately before the sale for the amount not yet deducted."

So, in the likely event that a PTP investor fails to use all of the EBIE amounts from a specific PTP prior to a complete disposition, those amounts are immediately released upon such a disposition - just like other accumulated PTP losses that were subject to limitations prior to the disposition. (I am setting aside the potential issue of a partial disposition, which would complicate this. TurboTax doesn't handle partial PTP dispositions well.)

What I really don't understand is why the IRS isn't clearer about how the items on Form 8990 relate to other tax forms - Form 1040 and its Schedule E in particular? I don't doubt that it is a small minority of taxpayers dealing with this, but a set of "helpful hints" guiding an average PTP investor through this would make compliance quite a bit easier.

Please comment if you see any problems with my understanding above. Thanks!

P.S.  I had the advantage here of having TurboTax Business, which allowed me to use the Form 8990 functionality there to hammer out the form.  Not ideal, as I had to create a "pseudo Form 1065" for myself to do it, but it seems to have worked - as long as I can correctly understand how Form 8990 relates to 1040 and its related schedules.