Now I spend 5 years hoping they make their payments and somehow refinance to pay off the balloon. 

I wouldn't spend another moment of my personal time on it. 

Use extended closing periods or additional earnest to buy more time for your old property to sell if you need.The last option is what's called a reverse exchange.

I understand that starting out, depending on how fast you want to build your portfolio, you could spend a lot of time at it.For those with established investment portfolios, how much time is required to maintain it?

Spending the owner's money, not saying anything, and letting them discover it while reviewing the monthly statement is unprofessional.

Quote from @Sofia Komrskova: Don't spend that kind of money on courses.

I’m an investor and the owner of a property management company based in Kokomo, with portfolios extending into the Indianapolis area.

Can you spend money on a CRM, automations, VA calling service, a VOIP phone system, etc?

If you spend time learning how to manage well, your income will increase, you'll save time, and you'll maintain your sanity with the courage to expand.

Spend your time and money learning how to avoid that kind of situation rather than learning from on the job training.