The channel's code default (GetDescriptor().DefaultAvailability).
The channel's code-default display (GetDescriptor().DisplayPolicy).
OptionalHostConfig the host supplied for it — a default that agent/app config overrides.
OptionalHostThe host declared this channel (it may have no registry row).
OptionalHostDisplay the host asked for — a default that agent/app config overrides.
The channel's key (its descriptor Key, i.e. its ChannelName).
The ceiling the channel can reach (GetDescriptor().MaxExposure).
Registry state, resolved by the caller.
One channel the session could have, with everything the scope decision needs.