The mod doesn't change scaling for starting area size, this is somewhat similar to vanilla where if you set starting area to max your first encounter with enemies will likely be at an already substantial evolution factor.
If you want to offset levels such that the first enemy bases around maxed out starting area are lvl 1 you can change the scaling offset in settings to around 1000.
When trying out different values of the setting keep in mind that it only applies to newly generated chunks.