How do I query if a binded key is unpressed and how long it has been pressed?

This is what I did in the mean time before the new feature is rolled out:

	@SubscribeEvent
	@SideOnly(Side.CLIENT)
	public void onKeyInput(InputEvent.KeyInputEvent event) {
		if (!FMLClientHandler.instance().isGUIOpen(GuiChat.class)) {
			if (org.lwjgl.input.Keyboard.getEventKey() == keys.getKeyCode() || org.lwjgl.input.Keyboard.isKeyDown(keys.getKeyCode()))  {
				myMod.PACKET_HANDLER.sendToServer(new KeyBindingPressedMessage(org.lwjgl.input.Keyboard.isKeyDown(keys.getKeyCode())));
			}
            // do this to maintain repeated key events. 
            // for some reason vanilla will turn this off when you open the gui
			if (!org.lwjgl.input.Keyboard.areRepeatEventsEnabled()) {
				org.lwjgl.input.Keyboard.enableRepeatEvents(true);
			}
		}
	}

	public static class KeyBindingPressedMessageHandler implements IMessageHandler<KeyBindingPressedMessage, IMessage> {
		@Override
		public IMessage onMessage(KeyBindingPressedMessage message, MessageContext context) {
			EntityPlayerMP entity = context.getServerHandler().player;
			entity.getServerWorld().addScheduledTask(() -> {
				World world = entity.world;
				int x = (int) entity.posX;
				int y = (int) entity.posY;
				int z = (int) entity.posZ;
				boolean is_pressed = (boolean) message.is_pressed;
				// security measure to prevent arbitrary chunk
				// generation
					if (!world.isBlockLoaded(new BlockPos(x, y, z)))
						return;
					{
						java.util.HashMap<String, Object> $_dependencies = new java.util.HashMap<>();
						$_dependencies.put("is_pressed", is_pressed);
						$_dependencies.put("entity", entity);
						$_dependencies.put("world", world);
						$_dependencies.put("x", x);
						$_dependencies.put("y", y);
						$_dependencies.put("z", z);
						MCreatorOnKeyPressedReleased.executeProcedure($_dependencies);
					}
				});
			return null;
		}
	}

	public static class KeyBindingPressedMessage implements IMessage {
		boolean is_pressed;

		public KeyBindingPressedMessage() {
		}

		public KeyBindingPressedMessage(boolean is_pressed) {
			this.is_pressed = is_pressed;
		}
		
		@Override
		public void toBytes(io.netty.buffer.ByteBuf buf) {
			buf.writeBoolean(is_pressed);
		}

		@Override
		public void fromBytes(io.netty.buffer.ByteBuf buf) {
			is_pressed = buf.readBoolean();
		}
	}

This will call your keybinding proc repeatedly when your key is pressed or released. It will also pass to your proc a dependency "is_pressed".