In general dashcam users prefer smaller files so there is less lost in case of a mishap. ( I use 3 minutess )
With the registrator viewer software it is just a matter of clicks with the mouse to export ( seamless and in original format and settings ) a multitude of smaller files into 1 large file, several hours long if you have driven for that long.
RV software will automatic detect your driving sessions on the memory card ( by time / date filename on files ) and assemble them into 1 session that you can play back in RV as 1 file or export as 1 single video file with a few clicks.
If you had a break between 2 driving sessions you can also easy add one to the other session and then view or output those 2 sessions as 1 seamless file.
Also if you camera is one of those that have some milliseconds of overlap on the individual files then RV can remove that too, just enter the value 1 time ( often 1000 ms ) and you will never have to think about that again.
RV can also be used to cut just a little out of a video segment, and you can edit out audio and any GPS meta data there might be in the footage, and maintain the original recording parameters and file format.
That is if your 512G is supported by RV, but i do think it is.
You can Dl RV here
https://streetguardian.info/support
same place there is also a few PDFs about using it, and there is videos about it on youtube too.