Yeah the low bitrate files do fall under the regular files, and so will of course be deleted when the memory card are full and it get to be their turn.
The Street guardian camera i use for parking mode generate 118 MB 3 minute parking files ( two of them as it is a dual system ) but thats a lot smaller then the regular recording files which are 3X larger
I think it is a okay setup, if they was all locked it would fill the assigned memory space sooner or later, and at least my camera it will also recycle the "protected" files eventually so the Read Only folder like the memory card in general never really fill up in the sense that it then stop recording.
As long as you keep the number of your events low and not having too many false events you will be good, i use the manual event button to save little stuff too, and i have a decent amount of files in the RO folder now, but i dont think the oldest files are getting deleted yet.
So as long as you dont get hammered in false or actual events, you will be good, even if you only look in your locked files every week or two, the content of my locked / RO folder go months back now, not least as i use another memory card for firmware updates so the main recording memory card dont get formatted very often,,,,,,, also intentionally as i am studying memory structure degradation from prolonged write / delete cycles.
you can try and create a hell of a lot false events, just to see how much will actually fit in your locked / RO folder, either by pressing the manual event button often, or flick the camera to set off the G-sensor.
I did that on my computer table with another SG camera, but i can not remember how many % of the memory card was set aside for events, or how many of there there was room for, but i do recall it was plenty and i saw no need to worry about the way things worked.
No harm in filling your locked folder, the regular driving are still in effect, but should you have a major event while doing that testing, i would of course take out the memory card shortly after that just to be on the safe side.
Actually i have the memory card of that camera right here by chance.
The 256GB card are full and recycling ( regular driving files at least )
In the event / RO folder i have 41.3GB of data in 112 files, and the oldest event file are from September 17 and thats also when the RO folder is created and so no recycling in the event / RO folder apparentl.
Where as the oldest regular driving file i have on the memory card are from January 24
I dont drive much on a weekly average probably something like 30 minutes a day MAX.