Thanks a lot to both of you. I ended up setting Auto Hold to On, because the users want to keep seeing the call details from Auto Display Waiting Call, for additional calls.
It would be good to be able to still make Hold visible, even if Auto hold is working, just so people can still explicitly hold, and in case they haven't yet been told that answering the other calls will auto-hold their current call.
Is there any way to modify the layout of the lower, white-on-black on-screen buttons, particularly when on a call, but also even when idel would be good. It seems like those are just hard set by firmware, but that seems like a shame, I imagine their might be a work-around. Does anyone know of any?