Correct, 1080 front and 720 rear. This has been a recent trend on most Korean dashcams. They say that stability is more important than having both channels 1080, so they do FullHD + HD instead of both FullHD. The only exeption I have seen is from latest Thinkware using 2Ch 1080p.
First time I heard about format free system being used on Korean dashcams was about 1y ago by
Blacksys BH-300H
They call it in Korea: TAT.
For the past 12 month or so I have seen 5-6 Korean dashcams with TAT ( format free ) systems.
TAT system is free from format unline FAT system. It makes memory card lifespan loner. Also minimize the Dead-secor thanks to formatting.
TAT Format Saving System makes it possible to record 1 second basis without super capacciy ( back up battery ).