Now, I took this and created a backup by going to 'File' > 'Backup copy' > 'Copy project and media into folder...'
I created a new folder on the desktop, then saved. Once the save was complete, I closed the program. I then verified that the folder contained the project and the media associated to it... I double clicked the project file, and it openned the Movie Edit Pro and loaded the project... audio too.
I am not sure I have done exactly as you have, but for my results, everything seems to be functioning correctly.
I too copy all projects to their own folders via Copy project and media into folder. (see earlier posted image.
It's not really a big issue ..... it only takes a few moments to generate the waveform when I reopen a project from a backedup folder.
You mention that the HO and HDP files are temporary...... I only know the HO extension is used for the audio wave form but don't understand what actually happens. Can you explain in a little more detail why / how they are used in the processing?
I'll check out Syncback (I'm not familiar with it).
Does SyncBack save a lot of space when using it to archive projects?
As far as I can tell the H0 files contains the peak data required by MEP to actually draw the audiowaveform.
The HDP files I guess contain the small still images you see on each video object - there are several references to the project folder and the video file name in them and some binary code which could be the image.
Syncback does not compress files it just copies them, however it has many options you can set when copying/synchronising such as adding filters of which file extensions not to copy eg the HO and HDP files - I use the freeware version