diff --git a/db/crud.go b/db/crud.go
index e974e6fe81..8499bb3409 100644
--- a/db/crud.go
+++ b/db/crud.go
@@ -3318,7 +3318,7 @@ func (db *DatabaseCollectionWithUser) CheckProposedVersion(ctx context.Context,
 		// previousVersion didn't match, but proposed version and server CV have matching source, and proposed version is newer
 		return ProposedRev_OK, ""
 	} else {
-		// Temporary (CBG-4466): check the full HLV that's being sent by CBL with proposeChanges messages.
+		// Temporary (CBG-4461): check the full HLV that's being sent by CBL with proposeChanges messages.
 		// If the current server cv is dominated by the incoming HLV (i.e. the incoming HLV has an entry for the same source
 		// with a version that's greater than or equal to the server's cv), then we can accept the proposed version.
 		proposedHLV, _, err := ExtractHLVFromBlipMessage(proposedHLVString)
diff --git a/rest/utilities_testing_blip_client.go b/rest/utilities_testing_blip_client.go
index 245a61e44f..b13f6fdb5d 100644
--- a/rest/utilities_testing_blip_client.go
+++ b/rest/utilities_testing_blip_client.go
@@ -1204,14 +1204,20 @@ func (btcc *BlipTesterCollectionClient) sendProposeChanges(ctx context.Context,
 		if i > 0 {
 			proposeChangesRequestBody.WriteString(",")
 		}
-		proposeChangesRequestBody.WriteString(fmt.Sprintf(`["%s","%s"`, change.docID, change.Rev()))
+		rev := change.Rev()
+		if btcc.UseHLV() {
+			// Until CBG-4461 is implemented the second value in the array is the full HLV.
+			rev += "," + change.historyStr()
+		}
+		fmt.Fprintf(proposeChangesRequestBody, `["%s","%s"`, change.docID, rev)
+
 		// write last known server version to support no-conflict mode
 		if serverVersion, ok := btcc.getLastReplicatedRev(change.docID); ok {
 			base.DebugfCtx(ctx, base.KeySGTest, "specifying last known server version for doc %s = %v", change.docID, serverVersion)
 			if btcc.UseHLV() {
-				proposeChangesRequestBody.WriteString(fmt.Sprintf(`,"%s"`, serverVersion.CV.String()))
+				fmt.Fprintf(proposeChangesRequestBody, `,"%s"`, serverVersion.CV.String())
 			} else {
-				proposeChangesRequestBody.WriteString(fmt.Sprintf(`,"%s"`, serverVersion.RevTreeID))
+				fmt.Fprintf(proposeChangesRequestBody, `,"%s"`, serverVersion.RevTreeID)
 			}
 		}
 		proposeChangesRequestBody.WriteString(`]`)
@@ -1274,6 +1280,11 @@ func (btcc *BlipTesterCollectionClient) sendRev(ctx context.Context, change prop
 		btcc.sendRev(ctx, change, false)
 		return
 	}
+	if errorCode == strconv.Itoa(http.StatusConflict) {
+		// If there is a conflict created between the preceding proposeChanges and this rev message.
+		// this is not an error.
+		return
+	}
 	require.NotContains(btcc.TB(), revResp.Properties, "Error-Domain", "unexpected error response from rev %#v", revResp)
 	base.DebugfCtx(ctx, base.KeySGTest, "peer acked rev %s / %v", change.docID, change.version)
 	btcc.updateLastReplicatedRev(change.docID, change.version, revRequest)