The Canarias phraseology is not ICAO compliant either
The point is a moot one therefore. They use a longer extra non standard word 'unrestricted', the UK use a shorter one 'now'.
ICAO should just bite the bullet and make it the same everywhere, for all stages of flight. An instrucion to climb or descend should cancel all previous restrictions regardless. End of story.
On the limited number of occasions where you do actually need someone to comply with a STAR or SID constraint, then you restate it, or you delay issuing the climb/descent so that the aircraft performance will ensure that it makes the restriction anyway. Not rocket science in my opinion.