You will not be able to use an MCC account, but rather connect all Ad Accounts that you want to report on. There is a one to one relationship for ChannelMix Profiles to AdWords Accounts so you may need to create extra profiles that will specify the account indicated in the connection. Often times, clients will create profiles specific to the ad account (ex. Alpha Brand - YouTube, Beta Brand - GDN, or Charlie Brand - 123-456-7891).
The Google Ads API now requires that you provide a "Manager ID" along with the ID of the Google Ads account. This will be the ID of the managing account, which may be the same as the Google Ads account ID if the account owner also manages the account, and this ID will not include dashes "-".