Hi @eventide0
Unfortunately, these can only be customised with CSS for now. Though, we do have this on our to-do list already for a future release that should bring these options right to the Customiser.
For now, please use the browser inspect tools to gather all the relevant classes and modify their margins. Something like this — https://ibb.co/r3vzv8x
Hope this points you in the right direction!
Thanks.