@Ned Carey has given a good explanation of the assignment process.

I can provide a fuller explanation but that's quick summary.

For qualification they include usually minimum payments on credit cards etc not the principal.If you're really low income, maybe it's better to find a lender who does "stated income" but there need to be proof: bank statement etc.I'd try another loan officer, maybe mortgage broker who would search for different options.Take a look at the topics here: there were explanations how Rental income would count and @Chris Mason even referred the source where to get the info first hand

However, the BRRRR calculator has no explanation of where Holding costs come from or where you need to input them. 

Thank you for that important information, wasn't sure if it was Ok or not to do it, but your explanation makes  a lot of sense!!

After some questioning and explanations, I was told that the offer was reduced to 287K based on nearby listings.

It was not left on the property, and he did not have an explanation for where it went.

As reference: Net Income ROI was listed as Year 1: 13.9% Year 2: 21.5% and Year 5: 34.0%                                      Cash ROI Year 1: 22.9% Year 2: 30.0% and Year 5: 39.3%                                      Total ROI Year 1 30.5%  Year 2: 38.0% and Year 5: 49.8%Thanks in advance for explanations.  

Thanks Kurt for your detailed explanation.

I've scoured the internet for workarounds or even a simple explanation of the intent of the code and haven't had much luck.