Can I temporarily adjust an answer for this one customer

Yes, but not in the supply chain file itself

Yes, you can. The supply chain file remains your single source of truth: that is where the answer that is actually correct stands, along with the supporting document that goes with it. What you adjust per client is the translation of that answer into the format and question wording of that specific list — not the underlying fact. If client A asks "do you hold an ISO 27001 certificate?" and client B asks "which Annex A measures have you implemented?", that is the same underlying status twice, but a different wording of the answer.

Where things go wrong is when that adjustment becomes a different fact instead of a different wording. A temporary adjustment "for this one client" that would contradict the file — for example, stating a higher number of employees because the client seems sensitive to that, when the number of employees the file shows a lower number — is no longer an adjustment but a different answer, and the system will not fill that in automatically for you. You confirm that kind of deviation yourself, separately, and that is permitted, but then you know that on that point you are deviating from the file and why.

What the system does and does not adjust for you

The system recognizes per client list which question corresponds to which underlying data point, and on that basis proposes the answer from the file — you confirm with yes or no, per answer, per client. That is therefore already a form of "adjusting per client": not to the fact, but to the match between question and answer. For a data point such as the registered address or the sector in which the enterprise operates that is usually unambiguous. With something like CSRD or VSME reporting, where the EFRAG VSME basic module allows for different levels of detail, the question can vary significantly in sharpness from client to client — the underlying figures remain the same, only the level of detail of the presentation differs.