Understanding the loan terms and their implications can help you assess the urgency and necessity of contributing to the cash call.

I use Avail for payments and they have a service that deals with urgency.

Due to urgency as the entire house had no drainage, I took care of it immediately.

We previewed properties and took our time as they had the luxury of NO URGENCY to make the right decision at the right time. 

No further improvements will be made to the unit going forward, and any repair requests will be responded to based upon the determined level of urgency required."

I get that it may take a couple of months to get the apartment rented but I sense a lack of urgency to get the unit listed.

I'd suggest not more than 6 months as you want there to be an urgency to collect the debt.Best tip to collect: Let the professionals handle it.

You can call property managers that work in the area and get an idea about vacancies for a particular area/neighborhood.You can ask your agent about DOM, urgency of the seller to move on from the property, how low is the seller willing to sell at, how many other offers there are, and so on.

I've had a PM that charged a flat fee and I assure you they have less urgency to fill a vacancy then a PM that, like you as the owner, is not getting paid due to vacancy. 

Might also create a sense of competition/urgency although not the prime directive here.