hasole When you use the "+ Add new file" option, the file is synced automatically immediately after adding. It should say "linked to ... " on the list. (If not then it's not working, and please contact me through email or website contact form, for me to get the sample file).
The "Automatic sync" button has been removed, as the app does it automatically now after adding.
I'm not sure what you mean with DCIM/RaceChrono ?