2 urls pointing to same VIP

Wouldn't it be easier if you just create 2 pools and apply the Irule.

Have a virtual created like below where it has a default pool and your sticky persistence in it,

ltm virtual testvirtual {
    destination 10.10.10.10:http
    ip-protocol tcp
    mask 255.255.255.255
    persist { cookie { } }
    pool abc_pool
    profiles { http { } tcp { } }
    rules { pool_selection_irule }
}

On the pools have LC as the LB method.

Then put the below code in the Irule pool_selection_irule: Where abc.com is the host where you dont want the persistence to be. And xyz.com is the host where your sticky persistence would be applied automatically.

when HTTP_REQUEST {
    switch [string tolower [HTTP::host]] {
        "abc.com" {
            pool abc_pool
            persist none
        }
        "xyz.com" {
            pool xyz_pool
        }
    }
}