Check the official terms, submit the application and nonrefundable fee, complete Form I-140G and supporting documents when USCIS instructs, undergo DHS vetting, and make the gift only after successful vetting. Re-verify the framework before each payment.
Verify twice: at research and at commitment
Hypothetical example: The two-check discipline exists because the framework's published terms have already changed once, and a household's own timeline may span the next change. The first reading supports the decision to explore the route; the second, immediately before money moves, confirms that the decision is still being made on current facts. Between them sit the questions that a household with corporate holdings must answer elsewhere: how a corporate arrangement interacts with Canadian tax and corporate law, and what the consequences would be if the structure had to change later.
Those are not immigration questions and should be put to the right advisers. If the second verification reveals that terms have moved, the correct response is to re-take the decision rather than to proceed on the strength of the earlier one.