I have a situation where a borrower purchased vacant land and intends to construct a primary residence on the land within 24 months.

RESPA reads: "If the proceeds will be used to locate
a manufactured home or construct a structure within two
years from the date of settlement, the loan is covered."

So, if the borrower is not necessarily using proceeds from the vacant land loan purchase to "start" the construction and rather, uses all of the proceeds to acquire the land, then it is NOT covered?

Correct.

Correct. It still would be covered under Regulation Z however.