The ReshardingTxnCloner is very conversvative when transferring retryable writes/transaction information from the donor. It just scans through the config.transactions table and convert them to IncompleteTransactionHistory records without attmepting to scan through the oplog history chain. This has a side effect of generating too many IncompleteTransactionHistory records on the recipients even though these transactions/retryable writes were originally from a different namespace.

This optimization has to also take into account special collections like time series (which has a different namespace name for the bucket collection)