I feel like sub-500 is possible since my solution has a period of 21 when it can be 20 with more careful construction. Then cut 10g of track, sprinkle some pixie dust and tada! 4xx! I also really wanted to make a 1/2p solution work, but it was always too expensive or used too much area (and only saved 20~30i). Can't wait to see what the top players did for this one that I don't.