Bigger sensors require bigger (and heavier) lenses and bigger, stronger gimbals.
Looking at the camera module on the Mavic 4, or the size of the X7 lenses, you can see that there won't be a bigger sensor.
Just to clarify are you specifying Megabits per second (Mbs) or Megabytes per second (MBs)?
SD cards are serial devices requiring a serial transfer so one byte of data requires transfer of each bit individually, one-by-one.
The figures quoted...
You never explained what it was about your RTH that didn't seem right and you had suspicions about the GPS.
It's only now that we find out that what you were concerned about was that the drone initiated RTH and you had the mistaken idea that RTH...