Because most HML's require it.

I only got one because I had to for a commercial loan on an 8-plex, the lender required it.

Zillows "zestimate" is an example.Lenders sometimes use them to expedite loan processing  and waive appraisal requirements.  

The policies can have blanket coverage for Additional Insureds (if required by written contract) and it is a flat fee.  

My REI experience and financials are "good to very good" when it comes to the basic DSCR requirements. 

After getting one set up, you will be required to renew it each year.

You can obviously continue using cash to buy your investments, but there are a number of options you can also use to finance both the purchase and then renovations that will require you to use less of your own money.

The other reason is that I want turn-key properties and not one that requires work as I am very inexperienced and do not want to take on a project.

Then the SDIRA would be required to pay taxes for that filing year. 

I think your biggest hurdle would be speed as these typically have seasoning requirements.