if it’s off, yes. charging is limited to 500ma. but if it’s running something cpu heavy and lighting a grid and charging you’ll want to use the charge we provide-- it’s 2.4A with a little over 5V to account for voltage drop over the cable at high current.
that said, i charge the norns off my macbook without issues, while running scripts and grids etc. basically norns will take all the power it can get, and apple computers are good at limiting current due to iphone charging etc.