The old thread is locked due to no activity/age so here is my hopefully more fault-tolerant attempt at a library.
I created a github repo for this at: https://github.com/kozbot/kecb
The main file of concern is kecb.py that uses ezdxf and numpy to generate files in ./dxf folder.
Instead of the original 10 units x 10 units in a 1/8" block I am now using:
UNITS_PER_BLOCK = 20.0
BLOCK_SIZE = 1.0 / 8.0 # Block size , assuming Imperial we are setting to 1/8"
For metric I would either leave block size as 1 (so it would effectively be 20mm x 20mm) or use 25.0/20.0 to keep them approximately the same printed size.