There is now a search feature in Dialer > Calling From that allows you to search by the friendly name of a phone number. Previously, only the phone number itself could be searched.
The new dialer could not call secondary phone numbers of a contact. We have now fixed it and you can now call any phone number associated with a contact.
With the new dialer, a user with an assigned phone number should by default be able to use their assigned number. In some cases, this was not the case. The problem has now been resolved. So, calls from a user with an assigned phone number will use their phone number by default.