I'm up to my bok with bok choy!! Seemed like EVERY seed sowed germinated. Thinning and transplanting but running out of space...keeping all plants and will make due. LOL
good timing. The seeds germinate readily. I would just discard the extras.
In zone 9b you can plant bok choy right now, as it it going to get cooler. That is the requirement for not bolting.
Even in my cool climate of PNW the spring plantings bolted in no time.