VR
Is depressurisation part of the elec smoke fumes drill on civil airliners?
Don't know of any where you would deliberately depressurise at high level ( for all the previously discussed reasons
)
There are some types where
after descending to a sensible level you possibly would depressurise in order to carry out items of the smoke removal checklist (e.g I seem to recall it was a possibility on the 744 but only at lower altitudes).
Deliberate depressurisation at high level is certainly not part of the drills on the 777.