WAN failover and ACLs

Hi Guys,

   I want to add a WAN failover function to my customer's ERL3 routers for some particulair VLANs. There is one ISP connected to each of two ERLs and the routers are connected via eth1 with each other. I´ve read several topics/ubnt manuals bud didn't find the answer. If I use an ACL in a VLAN inteface am I able to loadbalance (use this ACL for firewalling and loadbalancing in the same time)? It's hard to try this because the routers are deployed in production already. There are some PtP GRE over IPsec tunnels and OSPF whitch must stay funcinoal.

One of my VLAN intefaces:

vif 90 {
            address 192.168.9.253/24
            description HOST
            firewall {
                in {
                    name VLAN_HOST_in
                }
            }
            vrrp {
                vrrp-group 90 {
                    advertise-interval 1
                    authentication {
                        password VVV
                        type plaintext-password
                    }
                    preempt true
                    preempt-delay 3
                    priority 110
                    virtual-address 192.168.9.1/24
                }
            }
        }

One of my VLAN inteface ACLs:

name VLAN_HOST_in {
        default-action accept
        description "TEXT"
        rule 1 {
            action accept
            description "TEXT"
            log disable
            protocol icmp
            source {
                address 192.168.9.252
            }
        }
        rule 2 {
            action accept
            description "TEXT"
            log disable
            protocol tcp
            source {
                address 192.168.9.252
                port 8443
            }
        }
        rule 3 {
            action drop
            description "TEXT"
            destination {
                address 192.168.0.0/16
            }
            log disable
            protocol all
        }

How I plan to use the loadbalance future in commands:

set interfaces ethernet eth2 pppoe 0 default-route none
set protocols static interface-route 0.0.0.0/0 next-hop-interface pppoe0
set protocols static table 1 route 0.0.0.0/0 next-hop 192.168.11.50

set load-balance group WAN_FAILOVER interface pppoe0 route table default
set load-balance group WAN_FAILOVER interface pppoe0 route-test type ping target 8.8.8.8
set load-balance group WAN_FAILOVER interface eth1 route table 1
set load-balance group WAN_FAILOVER interface eth1 failover-only

set firewall group network-group PRIVATE_IPs network 192.168.0.0/16
set firewall group network-group PRIVATE_IPs network 172.16.0.0/12
set firewall group network-group PRIVATE_IPs network 10.0.0.0/8

set firewall modify VLAN_HOST_in rule 10 destination group network-group PRIVATE_IPs
set firewall modify VLAN_HOST_in rule 10 action modify
set firewall modify VLAN_HOST_in rule 10 modify table main

set firewall modify VLAN_HOST_in rule 20 action modify
set firewall modify VLAN_HOST_in rule 20 modify lb-group WAN_FAILOVER