We use Ring Doorbells and Cameras for our STR in Vermont.

A plumber can cost $250-$350/hr to put a camera in a drain line but a new sewer main can easily cost $30,000 - $50,000 and a new cleanout can be $6,000 - $8,000 or more depending on the depth and if it's by the driveway which it often is.

I have a commercial grade camera system watching the outside now. 

I didn't believe it until I saw the video from the store surveillance camera - and the tenant got a short-term loan from a friend, so he could pay.

Nothing that a camera and locator cant find to see the extent of the issues.

I do use other technology such as camera system.

It wouldn't hurt to have a camera sent down to see if there's a problem with the sewer line.

I have another building a better part of the city that does also have cameras, but those are run through the internet provider (which I have to switch away from at some point).

Those are what I would start with, but remote management is fine with a solid software, gate that syncs with it, and cameras.

We have outside video cameras and I've seen the fire pits left on for hours without anyone around -- looking forward to putting a stop to that!