This was disabled in bug 1652452. It's time we re-enable once bug 1644914 is fixed.

https://searchfox.org/mozilla-central/rev/7e36862b61622889b28492d60564dbab1e6d8bbf/docshell/shistory/nsSHistory.cpp#1262 may need some tweak, and in general need to check how it works with session-history-in-parent

I guess this should be unassigned? Please restore if not.

After looking through the parent bug 1645211, it would appear that bug 1645231, bug 1645218, and bug 1645220 are the bugs still relevant. I've had the pref enabled for some time on my local machine and things seem to be working well. Is there anything else that would be good to test before we try enabling on nightly again?