But we do want the option to use it as a short term rental in the future.Do I need to go the ADU route - separate address, utilities, etc?

We also currently have an LLC set up for our short term rental operations which we have been already running out of our spare room in our home which will cease when we rent it out.

I currently have two rental properties, but they are not "on purpose." 

What are the pros and cons of this type rental?

They have a convenient website where you can track your rentals and the money you are receiving from them.

But there are also a lot of run down rentals. 

triplex or fourplex will not satisfy self-sufficiency test as FHA requires that the property’s rental income covers 100% or more of the mortgage payment. 

However, this requires careful planning and adherence to 1031 rules.Holding and Renting Units:Retained Units: For the units you retain (one for your business and one for rental income), you will continue to benefit from rental income and potential appreciation.Depreciation: You can continue to depreciate the retained units, which provides additional tax benefits by offsetting rental income.With these considerations, this approach allows you to leverage the benefits of a 1031 exchange while maximizing the potential of your investment in the commercial property.

I don't follow the short term rental trends, but long term rentals are easy to get up and running with a good return. 

I have a rental condo in Denver that I need to do either a cashout refi or some kind of delayed financing on.