@HassanS6000 I just updated to that version of SpongeForge and Forge. The commands were still not working… But that was because the correct command would have a prefix of
/polis zonemobs <zone> ;
/polis addzonemob <zone> <mob> ;
/polis remzonemob <zone> <mob> . That was why the latest commands were not working - the command were simply wrong.
EDIT: On another note, the process works perfectly - just friendly reminder to unload the chunks to see changes.