Quanah,
Before I put any time into putting together a patch for syncrepl.c, I listened to what you said was generally recommended. I added the syncprov overlay to the consumer, even though it will never be a provider. I found that with the syncprov overlay after the syncrepl overlay in the config file, the DSA's CSN will still get out of sync. However, with the syncprov overlay before the syncrepl overlay - I have been running for the last three hours without any reports of the DSA's CSN being wrong on the replica (with one exception that was a check in the middle of an update and did not coincide with the missing csn value in the logs).
Therefore, I'm going to develop a doc patch to fix the guide and man pages rather than a code patch.