I've also been struggling to get this cutscene to trigger. I reinstalled a fresh save, and changed the datacrystal file before first launching the game, it now looks like this -
MezzStatus = { NumberofBoarDefeats : '3', ChaptOneTrainedEnd : '1', ChaptOneDelta : '12', TimesFucked : '1', TimesOral : '9', TimesAnal : '0',}
visited the island and returned to haven, walked past the alleyway, cutscene did not trigger.
1. Verify that the changes were saved correctly.
2. Where is the changed file located? Is it in www\js\plugins, as the instructions said? Changing the datacrystal.js file in the main directory of the game and failing to move it will not do anything.
I tested the most recent release by directly modifying the file to exactly the contents you listed below, and it correctly triggered the start of the scene ("!" icon and crash sound, which you then have to investigate further.)