I bolded one sentence I kind of glided over the first time I read it.
There is a topic in the USCF issues area:
viewtopic.php?f=5&t=17421
That mentions using the most recent rating. If the bolded sentence above is referring to the most recent supplement in MSA then that would be fine.
If it is instead referring to the most recent post-tournament rating then there is the following problem: a tournament can be rated in April giving an 1802 post-tournament rating that hits the supplement; in late June (after the July supplement is generated) it is rerated giving a 1799 post-tournament rating which is picked up by the progam and used for an event the first weekend in July; another re-rate that week of the April tournament returns to an 1802 rating; you end up with a post-tournament rating of 1802, a May supplement of 1802, no other supplement until the August supplement that includes the July tournament, no record anywhere of a 1799 rating, and an A player winning first place money in the class B section of a tournament with other players in that tournament complaining to the organizer and TD asking why they let this A player cheat and asking for a corrected prize fund to be paid out.