Until the publication of a major FCOM update 18 months ago, all airlines using RETO were using their own internally developed procedures.
All operators use procedures customised in some way or other from OEM SOPs, and the manufacturer has a process to grant a “no technical objection” where changes could affect systems. In this case it appears that the OEM technical analysis when they changed their manufacturer SOP was of greater depth.
A more serious example of where customised procedures are not always properly evaluated was the 777 crash at LHR where the evacuation checklist had been split between crew members leading to spar valves remaining open as the split interrupted the intended sequence of actions.