Usually they are allowed if they are used as a "supplemental" heat source.

I have one property in Melbourne and hope to purchase more to supplement my retirement.  

Either way you need your rent at market as opposed to supplementing your tenants rent every month.

Depending on the scale at which you plan to implement the software, I do recommend for large 3rd party solutions, supplementing some of the current software short-comings such as inspections, and maintenance asset tracking.

In that's the case maybe you'll need to supplement your pipeline to include some direct mail or wholesalers, etc.

I recommend using this loan because it enables you to buy a multi-family that need some repair at a good price, rehab the property to your standard and rent it out. 

I currently have an entire separate website, FB page, email, etc. simply as a means to supplement my bookings along side the major platforms.

Like here in Oregon we can do 3 in a year and no more than 5 in your portfolio.. this was to enable those with IRA funds to lend  .. but they do not hold themselves out as lenders. 

How you approach and ensure you are actually understanding what their needs are and motivations will enable you to ethically find opportunities. 

My time in the military has enabled me to save and rack up some nice investments, which is what qualifies me for the amount I need in Miami.