nRF9160 LTE modem coexistence interface

I'm trying to understand how to make use of the nRF9160 LTE modem coexistence interface in a design.  I started asking about this topic in another thread about the BLE Gateway sample app:

I've seen the spec entry for the LTE modem coexistence interface here:

However, I'm looking for more information.  Is there any further documentation of this interface?  In general, how is this interface intended to be used in a design?  Can you describe its use?  Can you give an example?

Without knowing more, I do still have some other questions:

Are these pins already handled in modem firmware or elsewhere in the SDK, or do they need to be supported by application code written by your users?  Is there source code that I can look at to help understand how the interface is used?

If already supported by code:

How is the interface enabled/disabled?

With COEX0, does a high input inhibit transmit by the LTE modem?

How is COEX1 intended to be used?  I don't understand what is meant by "Active high time mark pulse, which is synchronous to LTE system time.".

Thank you,