Per label, you can overseed 4 weeks after application of Quincept Herbicide.
What rate Quincept Herbicide is applied at depends on the area you are treating and types of weeds, ie ornamental turf, non turf areas. Please refer to the product label for your specific application.
Quincept Herbicide does list dollar weed on the product label and zoysia is listed as moderately tolerable so it is an option for post emergent control. It would be applied when the target weeds are actively growing and healthy. You can use Ferti-Lome Broadleaf Weed Control with Gallery as a pre-emergent for pennywort/dollarweed.
Replanting seed in bare spots where you have killed weeds will fill in the spots. You should wait 4 weeks after your Quincept Herbicide application before seeding in the same area.