By the way thank you the document . I did check the relavent sections . Section 9.1 says “ initiate a turn away from the assigned route or track before commencing the emergency descent; “ Considering how slow aircraft turn at high speeds / altitudes , there will be adequate time for ATC to be notified before the aircraft establishes the new heading to commence the emergency descent .
But when talking of ATC procedures , individual needs of each country might be different that’s why they publish CRARs and maybe one of them might include (or have included ) what I was talking about .
Give me sometime to gain complete access to all that stuff and I’ll dig it out