I’ve put a pair of green channel stacks of C/2022 E3 here:
https://nickdjames.com/comphot/Examples/2022E3/
The non-offset stack has been plate-solved but please re-do that with whatever tool you use. The offset stack is a sigma clip at the comet’s offset rate. It will have an identical zero point to the fixed stack.
Have a go at measuring the comet’s magnitude and coma diameter using these images and whatever tool you prefer. For consistency please use Gaia DR2 or 3 G magnitudes. It will be interesting to see what results we get.