For the most part, they all can be created and funded next year, with a few exceptions.

An audit could be triggered by a number of factors that don't line up when run through the IRS's system, and create an exception.

We follow a similar model as @Bill B. and with similar results, except our properties are from the 60s, so we gut them and rehab from the studs up, basically resetting the clock. 

Granted we only have 17 but still, I’ve never used anything except a simple excel spreadsheet and all my rental properties have a separate savings account under my main account at my local bank.

Only exception would be if you have a game room or extra living area that is far from the kitchen, then it would be a good idea. 

It does not cost the landlord except for the labor and materials.

It's pretty common practice to have something like that in a property management agreement, and if it falls under that limit they're going to pay it and not notify the owner except in regular monthly updates because it is below the threshold of what is an ordinary expense in the course of business.

My pricing is best on Airbnb (except for direct where the guest pays no platform fee).  

Numbers always look good on paper but between holding costs when acquiring and renovating property, closing costs on can also add up.I am not saying it cannot be done, as I did it with about 75 loans in a very similar fashion (except I was buying NPL's and got them reperforming).

Typically, we see it take several days except in PA because of the promothonotery or whatever its called for taxes in PA.