关于修改assigned CoS的问题

请教下如果Tier2 extension CoS已经assigned给我了,但在提交签证材料后发现HR把end date写晚了2周,导致延签时长为3年2周,可不可以在SMS系统上的sponsor note添加信息注明正确的日期,而不用cancel然后reassign?

我看到gov.uk上关于Create a CoS- Guide for business sponsors的PDF上是这样写的

HINTS AND TIPS ON CREATING A COS

You can use the ‘sponsor note’ field to amend minor errors identified after a CoS has
been created. Examples of acceptable amendments are:
• corrections to a mistyped name or date of birth;
• A change to the start date for the job.
You can also use the ‘sponsor note’ field if there is any additional information that you need to
state with regard to the migrant and/or the CoS for example, if the CoS is for a Tier 5 (Religious
Worker) CoS you must explain how the resident labour market test has been met by adding a
sponsor note.
A ‘sponsor note’ can only be added to a CoS that is showing in your SMS account with an
Assigned’ status.

end date的error程度应该和start date一样吧?我目前签证已经到期,因此希望在到期前提交的延签能够valid,如果需要cancel CoS,CW是不是肯定会据我已经提交的申请?