I have often truncated my rear fender so that it extends just far enough to keep rear wheel spray off my backside and the saddle. The arc of the fender is about (guessing) 130* instead of 180*. This leaves much of the rear of the rear wheel free to move back and forth without interfering with the fender, and let's you nonetheless have a regular arc in the remaining fender.
Now, I've never used track ends, only long horizontal dropouts -- move wheel forward instead of backward to remove, but perhaps my experience might apply to yours.
I've wondered whether the Rinko modification for rear fenders might not do double duty for removing fixed/ss rear wheels in track dropouts -- has anyone tried this? (This means a relatively QR setup to break the rear fender in half just aft of the bridge, for quick bike breakdown and portaging.)