iRule or Re-write Profile

Yes, you can try following rule.

when HTTP_REQUEST {
    if { [IP::client_addr] eq "x.x.x.x" } {
        pool pool_A
    }
    HTTP::header replace "Host" "host1.com"
}

when HTTP_RESPONSE {
    if { [HTTP::header exists "Location"] } {
        set location [HTTP::header "Location"]
        set updated_location [string map {"host1.com" "example.com"} $location]
        HTTP::header replace "Location" $updated_location
    }

    # Optional: content replacement if backend returns HTML with embedded URLs
    if { [HTTP::header "Content-Type"] contains "text/html" } {
        STREAM::enable
    }
}

when STREAM_MATCHED {
    STREAM::replace "host1.com" "example.com"
}

when HTTP_RESPONSE_DATA {
    # Needed for stream profile
}

please try above irule.