It sounds like the main issue you're addressing is that mortgages need to keep getting paid. New York City suspended mortgage payments however, so how were they able to do that without causing all the problems you're describing?
So the way these Deals are structured, you have "people in charge" of each deal, in simple terms. They also monitor all of these properties (Asset Managers) all the time. Right now they are basically marking them as "COVID" Forbearance. But that has been going on for some time now, and we are at risk of the bonds starting to default. I expect the Gov. to step in soon on this even more, but that will only buy a small amount of time. What needs to happen is to get tenants paying. It is a very complicated system that was never designed to handle something like this.
Except, of course, that tenants are not paying because the economy is being shut down in response to COVID. The better solution would be for the government to take over some fraction of the loans, large enough to prevent contagion but small enough to avoid zombie businesses. Not an easy balance to strike but probably the only way to see this through to the end of the crisis.