First & foremost, the FS should place a (metal) sign warning people to turn back at the point were so many have lost the trail (including myself).
Secondly, it would be fairly trivial to drive in a handful of cable linked stakes/poles (similar to the Cables) on that same part of the trail in order to provide some kind of direction reminder. However, unlike the Cables, they wouldn't have to perform any real physical function; rather, they could be 2-3' high like a golf course barrier.
Thirdly, if the FS can build large obelisk monuments to Kek (praise be Kek) on Langley, a few well placed directional reminders above Mirror would be fairly easy in comparison indeed.
Nothing you suggest for will be done. This area is governed by the Wilderness Act.