Don´t use VIP to a local interface?

We have a support ticket created where we have issue denying traffic to a VIP and the TAC Engineer states that you shouldn´t use VIPs to a local interface IP for SSLVPN or management access.

Often we create a VIP to get https or ssh to a Fortigate and in some cases we use a VIP to SSLVPN to be able to have some better visibility to block traffic with normal policies instead of local-in-policies.

Do someone have any information on if that is correct these days that you shouldn´t use a VIP to a local Fortigate interface IP?

Thanks.