the rope wear in the loop would become an issue.
Indeed, a permanently attached, in one point of the line, loop,
even if it is a double and "communicating" one ( so both eyes would bear evenly the same burden ), is condemned to suffer in its tip(s).
The only solution I can imagine is to move the point of the attachment "upwards" or "downwards" from time to time, so the inevitable wear would be somehow distributed along the line... Using the
Trucker s hitch / Sheepshank hybrid shown in this thread would also address this problem. In fact, I think that the problem of wear in the permanently attached loop would be the main reason for such a solution, because, in a common
Trucker s hitch, one can always remove the slack / adjust the tension by just pulling the Tail End itself, instead of the Sheepshank s bight ( especially if he has a metal hook at his second anchor point, as you do ).
