There is some additional information that wasn't mentioned in your post above which sheds a different light on the situation.  1.

In addition cash flow is taxed annually.  

Further, he can extend his “grace” period a further 30 days by paying us an additional $50k.So far, we’ve collected two $50,000 payments in the last i0 days plus the $36,000, or $136,000.

Cash from a self directed IRA How did you add value to the deal?

It has 3 units, an additional dwelling unit in the garden level, and 2 garage parking spaces (which I've come to realize are quite valuable where the property is). 

Any additional advice is helpful.

In addition to what other said, because some landlords don't increase their rents every year.

Additionally, take time now to build relationships with reliable vendors and contractors; having a go-to network for maintenance issues will save you time and stress.

I assume there’s additional language in the PPM, or at least I’d hope, but the language can get very confusing by that point and many LPs don’t understand what they’re reading.

If you feel ambitious, you could try a BRRR strategy adding additional equity to the subject home and then taking equity out of it to pay off either the HELOC or if you decided to the refinance the primary residence.