I think bug 1557401 is the real problem here
Bug 1314074 Comment 25 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
I think bug 1557401 is the real problem here which is kinda fallout from bug 1474285, which hasn't really had much work done since it was released. I think that profile per install based on directory location is not a great design to begin with; it should be keyed to something intrinsic to the Firefox binary, not the install or launch location.