After doing some initial research, Avail and Innago appears to be very popular Landlord software programs.

What's popular and saleable in one place isn't great in others.

Anything that is almost guaranteed to be used daily in your rentals (i.e. couches, bed, chairs), I'd try to invest in as much quality as you can for those specific items.Some store sites will let you filter for "contract grade" or "commercial grade" items - these are the sorts of furnishing that get put into higher-use commercial applications such as hotel lobbies, apartment building amenity spaces, etc. 

$29.99 Blink Video Doorbell - https://www.amazon.com/Blink-Video-Doorbell/dp/B08SG2MS3VA popular alternative to the Ring.

I am a mortgage broker and out-of-state real estate agent, I had one agent on-site and a GC/PM on-site too.

I host (2) RV sites for an owners property (he also has a cabin he rents out as an STR part time as well).

Cleveland is a very popular place for cash flow and some cities in Austin has done well in appreciation

Triple Net investments have gained a lot of popularity in the last 18 months and for good reason.

Any site developers here to discuss that? 

My model projects these can be without private or individual site water, power, bathrooms, and/ or wifi and still be worthy investments.