AMETHYST does not have this feature as it influences the integrity of the recording(we make use of the checksum to proof that the recoding was not tampered with).
AMETHYST does have a tagging feature. This will allow you to ‘mark’ from where the recording must be split into a second, etc. recording. It will however also have the full conversation in a recording. For more information see forum post: How do I tag a recording?.
Each one of the split recordings will have the checksum values(displayed under recording details as ‘MD5 checksum’ and ‘SHA256 checksum’):