The below code does nothing, although taken from the example provided in your Discord

console.log('Hiding items in JEI, pre-event');

events.listen('jei.hide.items', (event) => {
    console.log('Hiding items in JEI');
    // event.hide('/\\w+:\\w+_spawn_egg/');
    // event.hide('/minecraft:lingering_potion/');
    // event.hide('/minecraft:splash_potion/');
    event.hide('appliedenergistics2:facade');
});

The console log at the top shows in the log, the one within the event does not.
kubejs-2.7.2.56

I was incorrect, the event does fire, the script just needs to be a startup script. I am however unable to get it to work.
event.hide('/appliedenergistics2:facade/'); doesn't hide AE2 facades for some reason.