From the documentation:
This argument tells syncoid to set the recordsize on the target before writing any data to it matching the one set on the replication src. This only applies to initial sends.
Does that mean if I wanted to change the recordsize of the files in a dataset, I could make a new dataset with the desired recordsize (lets say going from 1M to 256K) and then syncoid tank/olddataset tank/newdataset would result with all the data on newdataset using 256 recordsize while maintaining snapshots?