Unfortunately the latest Chronos firmware doesn't embed any metadata in MP4 files. However if you captured any DNG files, the shutter speed is included as metadata which might serve as a clue for recalling the frame rate.
If you were always shooting at the max fps, you could simply cross reference the resolution of each MP4 with the max frame rate your Chronos reports for each of those.
You might want to consider specifying a folder path or file name to include metadata such as the recording frame rate, however this is user error prone- it would require training yourself to verify the encoding settings dialog prior to each save