Bonus if your lender also does the refinance perm debt as well, that way you can keep it all in house during the BRRRR process and not have to use two different lenders

You could try verbally saying you'd pay him a "bonus" if he finishes on time or quicker.

The bonus/silver lining is my toddler now thinks I "like to work on roofs for fun."

It's a good opportunity specially at your age, you will learn and get pay is a bonus.

That way, you get all of the accounting capabilities with the added bonus of other useful features.

FHA 3.5% down first, then Conventional 5% down Home Possible (if you qualify) 2nd, and then you still have your full VA entitlement to use 3rd with 0 down, and then if you still have bonus/secondary entitlement left over, you can use VA again for your 4th property. 

As an alternative you can invest in syndications that offer large first year bonus depreciation (as Charlie Jacques recommended).

We used tax returns, saved the part above the last rank when we got promoted, and career bonus we got...it all went into the pot for the next down payment. 

It’s marketed as a 3 bedroom but realistically it’s more like a 2 bedroom since the bonus room is through the masters.

Added bonus this gives you a bit of safety margin by creating an equity cushion.