For one of my multi-family properties, I chose to dig my toes in the sand and make extra payments on the principal until it was paid off. 

My order goes like this.1: Front of House (unless there is an extra special feature. think a Plane Jane house with a chef kitchen or over-the-top pool and patio area)2-5: Highlights of the best features of the house.

And extra credit cards could be hard to scale as you grow.

You think they would be more helpful but they just don't really care to do any extra.

If there aren't issues with this and it wouldn't be too much extra work, I'm really just looking for an additional tool to incentivize our borrowers/purchasers to keep paying timely each month. 

That $15k adds an extra $95 /month to the mortgage that these buyers will be paying for the next 30 years, crazy.  

Don’t waste time working on impossible or near impossible deals just because you have extra time; spend that time in efforts to find doable deals.2.

Throw in some extra costs like moving expenses, professional photos (a cost the STR PM may also need to pay depending on the quality of the existing photos), renter's and lessor's insurance and a listing on furnishedfinder to round out some of the start-up costs.

(it will take you 163 months to break even on your cash outlay by paying that extra towards principle).

It may sound nice to pay a 6% management fee but the extra fees can add up to be more than the other company that charges 10% with no additional fees.