I would definitely pull up Excel and do some of your own calculations to figure out how things will look.

Here's a bit more in detail about how rates are calculated for DSCR loans:1.

If I was them i would be calculating how much you got in payments subtract that from the amount you invested and then see how much that sums to .. 

Even if the deal U/C doesn't close, I will calculate the value based on the one deal at the end of the year. 

Aside from the risk of taking on the property with tenants, you may also have to purchase site unseen which makes it tough to calculate repair costs. 

Based on the purchase price, closing cost, agent fees and certain other items you will calculate (capitalize) a total number.

Here's a bit more in detail about how rates are calculated for DSCR loans:1.

Does the tax code say this directly or is this inferred from the mechanics of the bonus depreciation calculation?

In my experience, most of the online calculators are just taking an educated guess for you.

A heloc is also calculated at it's Max amount usage even if not used during underwriting for a new mortgage.Cash out is tax free and it can be used as an "Asset or Liquid reserve" on new approvals.