Do you get any blind spots with the camera being off centre?
No way should you mount it in the middle. Dashcams have a wide angle lens so there's absolutely no need for it to be in the centre
Another little tip for anyone installing a dashcam. Once it's set up go into the settings on the camera and set it so the screen turns off after a minute or two. Multiple reasons - That way there's no risk of it messing with any ambient/other sensors in the car, the passenger won't have to sit staring at a bright screen, it'll charge faster if it has a built in battery, people driving behind don't have to stare at it etc.
Only one thing bugs me more than seeing that
and that's people who have a cable hanging straight down from the dashcam and into the cigarette lighter port. There's so much space to hide the cables!!