This addon lets you set the EMC values of items and the Philosopher's Stone transformations blocks with the ProjectE mod. Examples are shown below.
Server side events (server_scripts/):
ProjectEEvents.setEMC(event => {
    // sets the absolute emc value of an item
    event.setEMC('minecraft:cobblestone', 0) // alias. setEMCAfter

    // sets the emc of an item before anything else happens
    // this can sometimes result in this emc value not being
    // set, but also it allows for emc values to be generated
    // from this one; i.e crafting recipes
    event.setEMCBefore('minecraft:stick', 10000);

ItemEvents.rightClicked('minecraft:stick', event => {
    let player = event.player;

    // getPlayerEMC will always return a string
    // because emc values can get very large
    player.tell('Your emc is ' + ProjectE.getPlayerEMC(player))

    ProjectE.addPlayerEMC(player, 1000);
    // the second argument can be a string because of the above
    // ProjectE.setPlayerEMC also exists

    player.tell('Your new emc is ' + ProjectE.getPlayerEMC(player))
Startup events (startup_scripts/):
ProjectEEvents.registerWorldTransmutations(event => {
    event.transform('minecraft:tnt', 'minecraft:oak_planks');