- Is there a way to complete an attended transfer without hanging up the handset/headset ? When our receptionist has multiple lines on hold, it is not practical to physically hang up the phone to pick it up right away. We would like to click again on the transfer button to finalize the transfer process (like we do on our Snom phones).

FOP2 does not control your phone, it controls the PBX. For that reason it is not possible to perform some actions that are centered on the phone, like answer/hangup. So, there is no way to do that, once the attendant transfer is launched, the call is managed by asterisk via the atxfer feature, and you can only continue using it as asterisk dictates (hang up to transfer).

- We the transfer is done, the CallerID number does not update on the fop interface. It still shows the receptionist number as the callerID, while it is correctly updated on the callee phone (Snom), using P-Asserted-Identity. Is there a way to do this in fop2 ?

FOP2 will display whatever callerid is being broadcasted via the AMI interface. It has no relation at all with the channel driver/protocol. Whatever you see as callerid is what gets published by asterisk in the AMI interface, so unfortunately it is a no again, as long not something you can do in FOP2 itself. You can think of FOP2 as a mirror, it will reflect whatever image it receives. It does not distort that image in any way.