For KubeJS, use the serverevents (yes also for singleplayer)
At kubejs/server_scripts/
create a new .js file: reciperemoval.js
Paste:
ServerEvents.recipes(event => {
let toRemove = [
{output: 'gtceu:hazmat_headpiece'},
{output: 'gtceu:hazmat_boots'},
{output: 'gtceu:hazmat_leggings'},
{output: 'gtceu:hazmat_chestpiece'},
];
for (const remove of toRemove) {
event.remove(remove);
}
})
Restart the game and test it again