Many of TALLOWAY's responses have some merit. Nonetheless, DFC does make a valid point that perhaps the UK has not fully implemented the ICAO SARPs for flight planning Alerting Service.
Perhaps the question is whether the UK system which '... have a system that works for everyone except DFC. Not a perfect system, but one which does the job.' is the same as one which meets the ICAO SARPs.
Maybe it is worth pointing out that the UK has filed a difference with respect to one of the SARPs in this area - so although DFC may want to have a whinge, the UK system is at least documented.