Change data capture and archivelog deletion

Hello,

I am using a third party change data capture(CDC) product that uses archivelogs for input.  We use an Oracle 12c RAC database.  After we back up archivelogs we keep them around on disk for several backups until CDC scrapes them sequentially for transactions it wants to replicate.  There is no communication between CDC and Oracle as to when CDC has finished processing the log.  We just estimate that we are keeping the log around enough (3 log backups).  It works, but is expensive because CDC has usually processed the log long before the delete policy removes it.   I do have