For example, I am underwriting a lot of multifamily properties in TX and OK and I would like to get more accurate ROT's for my expenses within these states.

It's a one-time transaction, and you'll have FIXED monthly payments and rate will typically be lower compared to HELOC.  

Do they have a rate cap and are escrowing funds to purchase the next cap, which is probably 10x as expensive?

My living expenses were almost completely rolled into the business model and I lived among an ever changing group of guests who made life lively and entertaining.

A hypothetical $150/mo fee to manage a 2k/mo home is tolerable, but a 150 fee to manage a 750/mo house hurts.Just make sure you factor in all of your expenses into your equation and don't just calculate your cashflow as being how much money you have after paying the mortgage.

This can get you a lower rate without doing FHA because that will come with a fee for the life of the loan.

We found out the property was an upper and lower rental and I talked to the landlord about cleaning up the garbage. 

I did not make them aware but included it with all my other documents and would have thought that seeing I had rental income and mortgage expense that they would have noticed or questioned what the cost segregation study was. 

One observation in working with higher loan amount borrowers and lenders recently is that rates can often be LOWER than conventional loan amounts. 

Third, develop a property management model and plan to keep expenses low and revenue high.