At some point I believe we decided that WSComm was responsible for stalling customize.ms stalling errors. However in Beta 10 I still have a couple stalling tasks.
0: INFO: Scene loaded successfully
0: INFO: Killed ADSK Communication Center process: WSCommCntr4
0: INFO: Executing script: C:\Users\renderadmin\AppData\Local\Thinkbox\Deadline6\slave\RENDER-I7-14\plugins\527d8a4eb5b7e119fcbd85dc\customize.ms