"pipewire should check what existing jack implementations do regarding monitor ports and follow it by default. the separate monitor ports as it does now I would say is non-standard. neither jack1 or jack2 behave this way." -Jack maintainer falkTX
I reported the issue dragging pipewire "Monitor" rectangle of each device in patchbay causes regular interface rectangle to be dragged behind along with it to the Carla & Jack maintainer falkTX. But like he says in that issue (I've quoted him in this comment title), the problem is not with Jack or Carla, but rather the responsibility instead lies on PipeWire's end to adhere too how jack behaves:
"pipewire should check what existing jack implementations do regarding monitor ports and follow it by default. the separate monitor ports as it does now I would say is non-standard. neither jack1 or jack2 behave this way."
"The idea has always been that pipewire is meant (on top of other things) to be a "stock" jack replacement. Whenever something is unclear, pipewire should just follow existing jack behaviour. It has been the case so far, so for this it cannot be any different."
"If something works under jack2 but is broken in pipewire, it will always be assumed to be pipewire issue, there is no discussion needed. Anything else would stop it from being a real replacement."
I would also quote from pipewire.org:
Seamless support for PulseAudio, JACK, ALSA and GStreamer applications.
and from PipeWire's git repo's readme:
Most audio applications can use either ALSA, JACK or PulseAudio as a backend. PipeWire provides support for all 3 backends. Depending on how your distribution has configured things this should just work automatically or with the provided scripts shown below.