While replacing the toilet, a burst pipe caused Cat 3 water damage that rendered large part of downstairs kitchen and upstairs bathroom unavailable and cordoned off for repairs .

i.e. getting outbid on offers, properties become unavailable before you get a chance to see them, etc...You are not alone!

Lots has changed over the years.Managing it yourself from a distance can be done, but it will require your team to be built and for you to have back up strategies if guests need attention and you're unavailable. 

This might give a one-time (non-scalable) boost to cash flow, offer multiple value-add options, and allow the house-hacker peace of mind, via the assumed mortgage, in long-term breakeven or positive cash flow in the event that the value-add plans end up not being executed, and/or the person has to move out, and rent by the room or STR become unavailable for some reason at a future date.

Does the fact that these were purchased separately and are at different locations make that option unavailable?

Solving the great mysteries of life, for all of us, generally requires time and bandwidth, resources unavailable if you're spending all your down time looking for the next off-market deal. 

While they are eager to sell the program—often because they receive a significant commission—many are unavailable or untrained to provide assistance after the sale.2.

In this business time is money and if I need to reach out to a possibly unavailable homeowner every time I need something, this will slow up the project.

If the residence is inside a gated subdivision or a controlled-access buildingthat is governed by an owner’s association, a letter from the association acknowledging the use and grantingaccess to occupants of the rental unit will be required as part of the application.A short-term residential rental requires a Conditional Use Verification (CUV).A short-term rental use is unavailable and prohibited within a residential unit or a room within a residentialunit that is located in an apartment building.

Property owners' and managers' sole recourse for encouraging residents to pay is unavailable.