However, there are types of tenants (similar to travel nurses in the US) which can be tapped into providing a consistent level of higher rents.

I maintain even break even on valuation (which is rare in SF Zoned areas), the ADU has big disadvantages versus new property acquisition including financing, level of effort, rent control, prop tax being based on cost rather than value added, length of time including length of time from first expenditures to first income, reduction of something from existing unit (in your case existing home lost its garage).Did you see starting next year Mf can add an ADU per unit up to 8 units without any affordable housing concessions?

I could go on and on, but suffice to say the devil is in the detail, not in the high level split.

Corporate transparency is already regulated at the state level.  

And networking will propel you to the next level.

Is this realtor providing you with the level of detail analytics that you need to make an informed decision?

The key is understanding your comfort level with managing multiple units right out of the gate.. 

Definitely a good thought for other markets if its financially feasible, but my thats not possible here in FL since we're right at sea level.

That helps bring back down you debt to income level.  

My property is in San Jose, CA and would be worth about $1M and the above insurance is at the same level as my homeowners and costs a little more (about 7% more).