Speed cannot be assumed. The current sequence is application and nonrefundable fee, USCIS-requested Form I-140G and supporting documents, DHS vetting, the gift after successful vetting, and EB-1 or EB-2 approval before lawful permanent residence.
Payment does not compress assessment
Hypothetical example: The attraction of a payment-based framework is usually the hope that it removes uncertainty, and that hope should be tested rather than relied upon. Vetting and admissibility take the time they take, and they are individual to each participant. A household selling a practice and planning a move around a school year needs a timeline it can defend, which means asking the official source what the process actually involves and at what points a decision is made.
It is also worth planning for the possibility that the framework's terms change during the household's own timeline, since that has already happened once. Where a date genuinely cannot move, the safer approach is to identify what the household would do if the framework were unavailable or slower than hoped, and to know that answer in advance.