Mostly into engineering time. Writing accurate technical descriptions, clearing internal material for release, and reviewing what can be shared all consume hours from people with other deadlines. Legal fees for the eligibility analysis and any filing are separate, and worth requesting as an itemized scope.
Budget the engineering hours explicitly
Teams routinely underestimate this and then produce rushed, generic statements that weaken the file. Name the contributors, agree how many hours each will give, and get that time protected in the sprint or on the roster. Ask whether the adviser will interview the technical lead directly, which usually produces better material for fewer total hours than sending a questionnaire into a busy team.
Add one item that is cheap and frequently omitted: a short assessment of the qualifying history before the engineering hours are committed. A career that includes contracting periods, a secondment, a transfer between group companies, or earlier time in the United States can change what is possible, and that arithmetic should be settled before a technical lead spends a week producing material. Ask for that assessment as its own small engagement with its own price, and agree what happens to the wider plan if the answer is unfavourable.
Hypothetical example: a network orchestration specialist's team schedules eighteen hours of engineering time to prepare documents, then discovers on review that an earlier period on a customer's payroll makes the qualifying year a question rather than an assumption — a question that could have been asked in the first hour for a fraction of what the eighteen cost.