28L - nice and simple and 'on the button'! Is there no CAP guidance on the R/T format?
A lot of the problems, in my opinion, come from the 'secret' - i.e. often not published on flight crew documentation, altitude 'targets' such as 'MARGO 260'. Sometimes it is there, sometimes it is not, and how long has THAT taken to get into the Thales book for EDI/GLA? It happens a lot outside UK at national handover points, completely unknown to crews unless they 'remember' it from before.
28L' s idea would be easy to follow. FMC is not an issue then. Descend now=descend now. Very simple.