I'm not massively familiar with the area, but looking on bustimes, the route seems fairly similar to the 9s other than Kilburn or Somercotes diversions. Running time is even the same.
It would seem to make sense to integrate it as say the 9.2, beyond Alfreton route it via Stonebroom and Morton to fix the issue with the 55.
Then, why not go radical? The Red Arrow which it split off is a premium, very limited stop route. Why not restore the Comet to this status, but extend it on to Sheffield. Clay Cross is lacking direct links, and Stagecoach don't want to target the very limited stop potential for this route. While the Comet and X17 times together come to around 1h55, cutting some stops and optimising the route could easily get that down to the point where it's viable for 4 buses with about 20 minutes recovery time on an hourly timetable.
Gives Wellglade another entry to Sheffield and a guaranteed presence after franchising as well.