As far as I can tell, I can set and change list filters using the contact lists API, but is it possible to set what columns are shown as well? For example, if I had a list of contact properties I wanted displayed as columns in a list? How would I modify a list with a given ID to show those columns?
At the moment, it is not possible to customize list columns via HubSpot APIs. However, you can do so via the HubSpot interface: Customize list columns.