Use the deadline in the actual notice and obtain advice promptly. This guide does not invent a universal Gold Card response period.
Work backward from the official instruction
Ask when counsel needs your materials for review and which records may take time to retrieve. Do not assume an extension is available or that a sent draft counts as a filed response. Preserve submission proof and keep monitoring, since timely delivery does not establish when adjudication will finish.
Work backward from the date in the notice and identify the point at which the plan fails, because that is the moment to seek advice rather than to accelerate. Ask when counsel needs your materials in order to review them properly, then ask which records may take longer than that to retrieve. Where the two do not reconcile, raise it immediately instead of hoping the retrieval will be quick.
Do not assume an extension is available, and do not treat a draft sent to an adviser as a filed response. Preserve proof of submission and keep monitoring afterwards, since delivering a response on time establishes nothing about when the adjudication will conclude. Confirm the deadline reading with counsel rather than interpreting the notice alone.
Note the date the notice was received as well as the date it was issued.