Hey there.
I've made some minor changes to "_zm_pack_a_punch.gsc", saved it in my map/scripts/zm folder and added it to the zone file:
scriptparsetree,scripts/zm/_zm_pack_a_punch.gsc

Those changes does not appear when running the map.  It appears that the mod tools does not compile this script.

What am I doing wrong? There are no errors or warnings from any kind...

There is currently an issue with editing most stock scripts in the beta. Can't do anything about it right now unfortunately, got to wait for a fix