The difficulty with this situation is that what is written in the proposed CE / actually instructed CE should determine the scope of the change. Although a quotation is required to include details of the assessment, the PM’s acceptance obligations are silent on what the PM should do to review a submitted quotation. It may be that, provided the total value is less than a certain amount, it will be accepted without the PM spending much time looking through the details.
The CE procedure doesn’t allow for a ‘battle of the forms’ type approach and a quotation is the Contractor’s assessment of what the PM has indicated in their notification. Consequently I would suggest that the change to the Works Informatiion is the PM’s ‘proposed change’.
People may say that the PM is not acting in a spirit of mutual trust and cooperation but their primary responsibility is to act as stated in the contract. What, ideally, should have occured is that the Contractor discussed with the PM alternative ways of dealing with the CE (note clause 62.1 doesn’t say who should instigate these discussions). Alternatively the Contractor may submit a quotation themselves, for other methods of dealing with the CE, without such a discussion. Note that in both these instances a quotation which relates to the instructed CE must still also be submitted.