I donīt know about postprocesing, but you can divide an active toolpath by angle,direction,lenght and time and make individual
programs using those resulting toolpaths. You can also limit a toolpath with plane,polygon or boundary and choose either to save inner, outer or both. You can also choose to save the original or not.
Ps. Doesnīt your controll allow to transmit blockwise? I use that method with TNC355,which can take in max 1000 blocks.