They aren't that secure (anyone with a crowbar could access a locked one), so I think next time I'll stick an outdoor web camera facing them. 

I would like to add some cameras that we can access buy phone remotely.

This property nets a solid double digit ROI.

I've also installed cameras around the property but that's done little to remedy the situation. 

A quick search online found a Digital Trend article with a variety of options, both mobile and desktop to look into. https://www.digitaltrends.com/photography/how-to-make-a-watermark/

Has anyone ever used digital locks for long term rentals?

I don’t want tenants who hesitate to report something I should fix sooner rather than later. 4) Tenants are more likely to share photo of the issue on the spot since you just tap the camera button.

Compared to previous years we're seeing lower days on market and prices increases year over year in the double digits.

Most Security systems only maintain footage for 2 weeks due to camera memory capacity.I.

The first indication I should have known it was a bad deal was when I was notified the prop mgmt company did not communicate through email or have any digital files.