I discovered today that Cx File Explorer (free from the Play Store) has a nice FTP service that lets you transfer .ts recordings to other devices (for example, on my iPad, the free version of FTPManager from Skyjos) quite cleanly.
I leave this note here for others seeking this kind of information, and for my own future reference.
I’ve given up trying to push edited video back into MyTVOnline’s recordings database. It may be possible, but in my experience it’s a nitpicky and fragile process. Instead, I put edited videos onto my private Plex server on my NAS, which is better suited to the task, and play them through the Plex client on my Formuler.
I used to disconnect the recordings HDD from my Formuler, connect the HDD to my Mac and access/copy/edit the .ts videos on the Mac. But this is inconvenient if you just want to grab one or two videos from the Formuler. The FTP approach I mention above is better, unless you want to move a lot of large files at once, in which case it may be faster to move the HDD instead.
(An old, somewhat related thread: Rename a Recording)