Timed Gameplay is possible in BO3 by overriding specific functions running in _zm.gsc. This is necessary because _zm.gsc is not directly editable at this time (Modtools Beta).
If you are already overriding any of the functions used in this script, simply take that code out of the file and add it to your existing override function.
Currently this is an adapted script from the upcoming version of UGX Mod for BO3. The script will be improved over time after some feedback.
Download ugxmods_timedgp.gsc (version 1.0) and place it in root/usermaps/mapname/scripts/zm
Add this line to the top of your mapname.gsc:
Add this line to your mapname.zone:
You should see a timer in the lower left corner of the screen now and zombies should continuously spawn without delay for the entire game. Currently we have not found a way to hide the round counter yet but we are working on it.