I would say yes except for you're being on 9.1.
The IP Office supports 'simultaneous' mode for users, so you can be logged in on Equinox and a desk phone at the same time. You can even answer/make calls on each at the same time (it was this that lead me to understand why it had suddenly become possible to transfer a call to yourself).
In 11.0 they added support for what they call 'simultaneous anywhere'. That allows you to have your deskphone registered on one system and the softphone client registered on another - previously they had to both register to the same server which in a large network, could be awkward (especially if you wanted routing to allow remote softphone connections).
But simultaneous mode support is not largely documented and I can't say hand on heart when it started being supported.
What happens when you try to login the Equinox using the deskphone user's settings.
Stuck in a never ending cycle of file copying.