I am working on moving JSC EWS queues from old EWS to new EWS. I am trying to clearly understand various JSC EWS queues. I have few questions:

1) What does 'jsc-only' port represent? From https://trac.webkit.org/browser/webkit/trunk/Tools/Scripts/webkitpy/common/config/ews.json#L45 it seems like Apple JSC EWS uses 'mac' port, while linux jsc EWSes use 'jsc-only' port. Is jsc-only port specific to linux? Is there a corresponding jsc port for mac?

2) Is there any difference between the three linux JSC EWSes (JSC i386, JSC MIPS32el, JSC Armv7) apart from the architecture and few queues running/skipping tests? 

3) Where is the architecture for various linux JSC EWS queues configured in the old EWS code (e.g.: I don't see the architecture being added in https://trac.webkit.org/changeset/237001/webkit)? Is the queue configuration for various JSC EWS queues same, and the device connected to the queue actually decides the architecture?

Thanks

Aakash