Russia and China continue to use QFE and metric heights and levels.
They never use QNH - They might (maybe) issue a QNH...
When I flew into these areas, we were QFE qualified, flew QFE and had metric altimeter.
I think Laos still uses it. North Korea does QFE metric. I think Vietnam is now using QNH.
Some areas are more complicated. UK, as an example.
UK, at times, use QFE, then QNH, then... QNE/STD...
xxx
My opinion, if you fly Russia or China, you better be fully QFE trained.
And your aircraft better have a metric altimeter.
Many disregard this advice. Until they will make a bad mistake.
xxx
Happy contrails