iRule to reference data group for whitelisting IP

You can log the unblocked requests from within the local traffic policy. (I had log statements in both my rules, but removed them for the answer above.) There is a log action that can be added on the disable ASM rule. For example:

ltm policy disable_asm_for_select_IPs {
    controls { asm }
    last-modified 2020-12-03:15:50:12
    requires { http tcp }
    rules {
        disable_asm_for_select_IPs {
            actions {
                0 {
                    asm
                    disable
                }
                1 {
                    log
                    write
                    facility local0
                    message "tcl:ASM disabled for allowed IP [IP::client_addr]"
                    priority info
                }
            }
            conditions {
                0 {
                    tcp
                    address
                    matches
                    datagroup no_ASM_IPs
                }
            }
        }
        enable_asm_for_all_traffic {
            actions {
                0 {
                    asm
                    enable
                    policy /Common/lab_8_manual
                }
            }
            ordinal 1
        }
    }
    status published
    strategy first-match
}