Well there is redundancy in if one die the other still go on, but ill argue that is only a half truth, i jumped on dual channel cameras the moment i got the chance back in the day, CUZ i was tired of going to multiple cameras to get the memory card from them.
Though in all fairness back then my addiction was stronger and i pulled footage more often than i do today, also if you dont do that to share idiot drivers on your roads, well then hopefully you only have to pull the memory card to look at the footage every few months.
And you should do that CUZ even now +10 years after i got into this game there are no set and forget system.
It is no problem, well on a PC with the memory card in a card reader, it take me about 5 -10 minutes to look over a full 256 GB memory card.
What i focus on doing that is first and last drive in drive sessions, so first recording should be the back yard i park in, any following stops could be where i shop - my favorite gas station - friends or family's homes.
If you suddenly have something that start / stop in some randon place down a road, well then you might have a problem and you should investigate further.
Keeping in mide that any events on your drive, those will go to the RO folder ( Read Only or other name for the locked event folder ) so they will be missing from the string of clips of course.
I personally use the manual event button to save things, and then i say out loud what triggered me to do so, CUZ when i go for the footage a month later i cant remember why, a big + is some cameras also snap a picture the moment you press the button, that help a lot zeroing into the actual thing, which are some times minor.
I just play enough seconds of each clip i inspect that i can see where it is, i can of course not remember those drives CUZ in my case not driving much, well on a 256 GB memory card i have footage going back 10 - 14 days.
After i have checked my first and last recordings i just pik some radome ones too, and these i might play a bit more of, even if a file is corrupted it is generally all of it, so if you can play the first few seconds the rest should be fine too.
I personally just use a regular software player on my PC, the dedicated dashcam players i do not need, i know / can see where i drive just fine, my sole interest is the video itself and the time/date & speed embedded in the video.
The user Dashmellow are the dashcam in truck expert, thats all he drive living half way up some mountain over there.
The trucks are a little challenging, well at least in regard to the rear camera, some cabins you have a sliding window in the back window in the cabin, and there also is the issue of the bed, it will take up quite a bit of the footage, and if the car behind had a plate in the front to see, well the rear hatch will block that many yards out back, probably so many that when you can see the plate you can not read it as its that far away.
Then again a plate capture are not a must to deduct who is to blame, and after all not all run or are able to run after a alteration.
Of course some dashcam brands provide rear cameras that are waterproof and for mounting all the way on the back of a truck or van, but as you probably know a lot of crud build up there, so i do not consider this a good idea.
Since the dual cameras came about, the faults have gone up as there are now 2 places where a error can happen, but it is rare it is the camera unit itself, but broken cables and to some extend also lose plugs have been seen.
That is why if a user with a erratic behaving 2 channel system come asking for help, the first we ask of him / her is to disconnect the rear camera at the front unit, to see if the front camera alone work just fine.
It is not something that happen a lot, but often enough i have often wondered why i have not seen this problem myself as after all i have been doing 2 channel systems for many years now, and some times well a new system are just " thrown " into my car.
But i assume some are throwing a lot harder than i am