Would it be possible to make a config option for the size of each tier in the config file kind of like this?
tinycompactmachinesize=3
smallcompactmachinesize=5
normalcompactmachinesize=7
bigcompactmachinesize=9
giantcompactmachinesize=11
`maximumcompactmachinesize=13``

Most likely won't happen. The size of the biggest CM is capped at the size of 13 to really only load obe chunk per machine in the CM dimension when nobody is in the dimension.

This.
I've also started working on CompactMachines2, a rewrite of the mod for 1.10 with some major changes, there won't be another 1.7.10 version.