Ability to change IP addresses of Heartbeat network interfaces
Now the IP addresses for the heartbeat network are predefined and there is no officially supported way to change them, meaning that you need a dedicated, separate network for this purpose. In a virtualised infrastructure it is really not efficient as you have a bit limited number of vlans. with the ability to change these ip addresses, these HA pairs could share 1 vlan for this purpose.
Not only changing the IP address of the interface but also being able to VLAN tag the interface and to assign it to a LAG group.