Only thing you can do, if possible are entering custom values for the G-sensor.
Back in the day when i used this ( personal opinion BS ) i had to go for a drive or rather several and then use the lukas player to see what size events the G.sensor registered on my drive, and then use lukas viewer to enter the custom values.
Off course you can not use the lukas viewer for a blackvue product, but maybe their software support the same.
It is a common problem for many cameras, either you cant get the camera insensetive enough to not create event files all the time, or the other way around in some cases where you can not get the camera sensitive enough to make a event recording at all.
Personally i dropped the G-sensor cuz my lukas recorded all the time anyway so i would never miss a event anyway, but if i had a event it wasent saved in a write protected folder, but with a normal sized memory card i dont feel that's a problem as you have 4+ hours before the camera get to where it want to delete your interesting file.
And if your car get hit while driving i am sure you will notice it, and if its bad you will not be driving any more anyway so your recording of the event should be safe if you or rescue people turn off your car which i am sure will happen as its otherwise a hazard for you and their work.
I would only use G-sensor for parking guard if i was to use that one day.