Thank you for the time you took to type up that great explanation, pprune Radar
I think perhaps the two greatest issues facing IFR/airways pilots are
1) Ensuring that their flight is elevated to the airways ASAP - I have tended to think that filing for FL100+ does this but it looks like it is more complex.
2) If going to an airport OCAS, getting dropped out of CAS too early. AIUI, there is no solution to this.
AFPEx will (I presume .. never having had to do one) cope with the submission of a Change message (CHG), but that assumes you had it available. NATS also publishes the contact details for their FPRSA positions, so a call to them can often get your change input quickly if needed.
Sure it will - AFPEx does everything including making the tea - but there is no practical way to access it from the cockpit while airborne. I do have a primitive internet access via a satellite phone (for weather data, mainly) but the AFPEx terminal application is a 5MB download every time it is started up, and this is completely infeasible over anything short of a massively expensive "bizjet-level" DSL satellite data connection.
One bizzare solution would be to use the satellite phone to phone up somebody and get them to log onto the system and send out the message.
By "FPRSA positions" do you mean the two public IFPS desk numbers in Brussels? I do have those. A lot of people thought they were confidential but they are not.