Platform 13B and Platform 14B at Manchester Piccadilly (rarely used, for early morning/late evening turnarounds, such as TfW Manchester - Chester services. Also for late running trains and/or blockages at Castlefield or Longsight).
Platform 1 at Manchester Oxford Road (rarely used now, only used if there is a blockage on the Castlefield corridor and/or trains needing to terminate at Oxford Road in either direction).
Platform 0 at Stockport (rarely used now since pandemic, trains to Hazel Grove/Buxton/Sheffield/Cleethorpes/Nottingham/Norwich go to/use Platform 1 now instead). Similarly Platform 3B also (examples have already been mentioned).
Platform 3 at Macclesfield / Sandbach (rarely used, only used to move late running trains out of the way for intercity/express trains to pass. Macclesfield may still use theirs for any Manchester bound terminators).