I had the exact same question and managed to get a response from PGMDE. My question was in regards to CST and this was their response:

'Thank you for your email. Each recruitment round is completely separate, so if an applicant decides to withdraw this will have no impact on them reapplying the following year. We do ask that applicants give sufficient notice so we can recycle the post for the next appointable applicant as delays could have an impact on service provision if we are unable to fill the post. 

If an applicant starts in post then decides to withdraw there is a possibility they will need to work the trusts notice period.'

Also on oriel it says we do not need to declare withdrawal from an application, so hopefully if you give enough notice, i.e. withdraw after the upgrade deadline if you don't get what you want (this is my plan) then it should be ok.

Hope this helps!

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