Jackaudiosrc: setting more than 2 channels seems impossible

General Discussion
1

I need to be able to connect multi-channel audio between machines, using JACK sources on both sides. Unfortunately, the jackaudiosrc plugin seems to only accept 1 to 2 channels as caps, although gst-inspect advertises the following:

    Capabilities:
      audio/x-raw
                 format: F32LE
                 layout: interleaved
                   rate: [ 1, 2147483647 ]
               channels: [ 1, 2147483647 ]

… so up to 2147483647 channels should be supported as I understand.

Running the following test command fails with a streaming stopped, reason not-negotiated (-4) error:

gst-launch-1.0 -vvv jackaudiosrc connect=none client-name="test" ! 'audio/x-raw, channels=4' ! fakesink

Of course, I could interleave and have multiple jackaudiosrc clients for the same pipeline, but I’d like to use a more elegant way.

Am I missing something?