If you’re ok with leaving money on the table for the sake of family (which is absolutely ok) then go in with that expectation.

Since you most likely did not make the transaction right on Jan 1st, you will most likely need to consult the IRS table if you want to be precise in the amount you can depreciate the first year. 

(I think in-person is probably off the table right now due to Covid??)  

Please keep in mind even though they are are not a traditional lending institution they still may go off of your credit, your income, experience, and how much capital you have have to put down towards any investment opportunity, mainly looking for how much skin in the game can you bring to the table and ability to back it up.

I plugged some numbers in the calculator on calculator.net here.I'm having a tough time figuring out how they are calculating that last column in the table: Return (IRR).I'm trying to plug some of these numbers into the IRR function on google sheets so i can try to figure out how they're coming up with those values. 

Total project cost was around $126,000, and I had to bring about $20k to the table, with origination fees etc.

Many real estate agents in the market will know who the flippers/rehabbers are too.Out of curiosity, I am guessing you plan on bringing the cash to the table and the flipper will bring their expertise and contractor connections? 

Instead, we rely on the 30-yr old Revenue Procedure 87-56 which contains multiple tables, including defining industry-specific Asset Classes.

What I found out later after I emailed biosweep, is they included the recommendation in the final invoice to install a French drain system on the side of the home.

Don't worry about the money, in the beginning, the goal is to build a track record of being profitable and getting to the closing table.