To be fair reverserunlocked didn't claim that after the survivable crash landing the aircraft would be flyable again!
FWIW numbers from the AAIB report on the BA777 accident at LHR:
The aircraft’s initial impact was at a descent rate of about 1,400 fpm
and a peak normal load of about 2.9g.
As we know they ended up sans gear and there were a handful of injuries caused by debris entering the fuselage.
FWIW I'm still of the opinion that a "coached" via radio autoland is by far the simmers/PPLrs best chance of producing something survivable
at the first attempt on a real machine , IMHO probably the only option that might give you odds of surviving of above 50%. If they are not coached, and/or the automatics are disengaged the odds of producing anything survivable would plummet (poor choice of words
)