On a brief (cold) spin on the bike last night, I noticed an NCN sticker which wasn't there last time I cycled along that road.

Turns out NCN 54 now runs from somewhere near Burton (Etwall probably, I haven't found the start of this bit yet) to Uttoxeter. The NCN signs are fairly intermittent from Sudbury, and Uttoxeter appears to be the end of route for now. But given that route 54 also runs from Etwall via Derby to Little Eaton, and Etwall via Burton to Lichfield, either it's planned as a Y-shaped fork or a P-like loop.

Fortunately I ended up at Uttoxeter just in time to get the train back. (Back as far as Tutbury & Hatton, anyway, which is fairly near to Burton, and avoids a tedious wait for a connection at Derby.)