The B777 FMC makes provision for QFE operations (at least the one that I fly, other customer options may vary). Thank goodness we don't go anywhere where the QFE dinasour is still rampant, but we keep it on the books and in the software in case the commercial department dreams up some new destination where it prevails.
The potential for disaster with varying Altimetry procedures is enormous, the sooner that we can rid ourselves of QFE and Metric Altitudes, and make RVSM global the better. The only lingering problem then would be varying Transition Altitudes/Levels, but that one is tougher due to enormous variation in 'worst case' terrain in various regions across the world.