The task must be configured to be partial reload. I know where the setting is in Publisher but I'm not sure about it without Publisher. In any case, it does not depend on the trigger.
You can work that around and warp several pieces of script using IF and variables you can pass using this tool instead of QMSEDX.exe, so you only load what you want:
IF '$(vReloadMaster)' = 'YES' THEN MasterData: LOAD *; SQL SELECT * FROM Master; END IF
QvEDXTrigger.exe --task="PartialReload" --variable=vReloadMaster --values='YES'
Hope that helps.