Almost all of my reservations on points are rebooked multiple times. Some several days in a row.

The price seems to be updated once a day or so, and it is my daily habit to check all upcoming reservations every day. My very limited experience show price drop very far in advance (i.e, 11-10 months) and close to the stay date (which is more variable).

As there is no downside to repricing, apart from your time, there is no reason not to do it every time you see a price drop.