active-passive HA in AWS in two different AZs

[Adam_Cloud]

I deployed FortiGate-VM in AWS region based on "FortiOS_6.2_AWS_Cookbook" chapter: "Deploying FortiGate-VM active passive HA AWS between multiple zones manually with Transit Gateway integration" that meets our needs. Guide is not clear for me because it states to configure separate IPs for port1 and port2 on HA1 and HA2 but configuration is synced between peers once cluster is formed so for example if I assign:

>HA1/Master Availability Zone: euw1-az1 Public (port1): 10.20.0.5/255.255.255.0 Internal (port2): 10.20.1.5/255.255.255.0

>HA2/Slave Availability Zone: euw1-az2 Public (port1): 10.20.10.5/255.255.255.0 Internal (port2): 10.20.11.5/255.255.255.0

port1 and port 2 IPs on HA2 are overridden by master unit and Slave has the same IPs as Master. once joins the cluster. As workaround, I created secondary IPs on cluster port1 along with routing monitoring:

Public (port1) primary IP: 10.20.0.5/255.255.255.0 secondary IP: 10.20.10.5/255.255.255.0

Internal (port2): primary IP: 10.20.1.5/255.255.255.0 secondary IP: 10.20.11.5/255.255.255.0

Let me know if there is any batter solution to deal with this ? Did I miss something ?

Thanks for help!