I have some suggestion if you're thinking to update the mod. I tested the mod and it seems that we're unable to play CS_COUNTER and FX-TEST cutscene at the current version where actually you can manage them to work. Instead of using PlayCutsceneWithLoad, you can alternatively start cutscene by building it up and execute them manually.
There are four principal function to play cutscenes manually, they are LoadCutscene, CutSceneSetActionNode, LoadCutsceneSound, and StartCutscene. Since CS_COUNTER and FX-TEST audio files were missing, the LoadCutsceneSound will stuck trying to find the specified name but it doesn't exist in the game files.
To prevent that, you should replace the audio name with others and put StartCutscene function to play.
LoadCutscene("CS_COUNTER")
CutSceneSetActionNode("CS_COUNTER")
LoadCutsceneSound("1-01") -- i put 1_01 audio instead
repeat
Wait(0)
until IsCutsceneLoaded()
StartCutscene()
In the end, after you seeing enough of it you can end the cutscene via StopCutscene.
repeat
Wait(0)
until IsButtonBeingPressed(7, 0)
StopCutscene()