The Omnicities were last present en masse on the 685 around March 2020 pre Lockdown 1.  And then disappeared during Lockdown 1.  There was a brief foray of the odd one mid 2020.  But, as other have said, they became unreliable.  Prior to March 2020, and in 2019, VDLs started appearing to cover Omnicity failures.

The number 1 requirement for whatever goes on on the 685 has to be reliability and to do the roundtrip with no problems.  The 3 roundtrips per day are 330 miles.  I calculated the 2 Stagecoach 64 reg E300s were doing 110k miles per year each due to being out all day nearly every day.

Stagecoach Cumbria also had the odd reliability problem when using 55 reg ALX400s about 2 years ago when there were various school related topics all came together giving rise to more pupils on ther buses.  Hence why Stagecoach now use the 68 reg MMCs.

The Arriva E400 does one afternoon roundtrip to pass back through Brampton at schools out time.

I personally have found the VDLs much more comfortable than the Omnicities.  The VDLs are a softer ride.  The Omnicities even after their refurb and green repaint still had a boneshaker ride tendency - harder seats and harder suspension but the refurb did seem to cure the worst of the exhaust gas interior recirculation issues.

Why not look on the branding as an allover advert? Somewhere else for the local north tyneside passengers to have a day out?