Triadic. There is of course a chance that the system has been made more labour intensive as that makes more jobs and more penalty rate time!
Possible, but don't know??
Any flight plan or notification with a SARTIME should go via the AFTN to CENSAR who then monitor it. Any ATS unit accepting an amendment or cancellation should then advise CENSAR via whatever means they have in their procedures.
If it is not cancelled then the holder of the SARTIME, in this case CENSAR should contact the relevant ATS unit for further information. It used to be that at SARTIME plus 30 min a Uncertainty SAR phase would be declared which would up the anti and formalise the process. If no info was forthcoming, then the phase would usually be upgraded at fuel exhaustion time or on receipt of other info. A simple process - at least it was. As for now, who knows?