Enable "warm custom tracking domain" when importing csv

In the csv you upload you can set settings like daily warm limit and increase rate, but there was no option in the sample to enable this feature in the SS or to specify a tracking domain for each email account in the spreadsheet

I want domain A to be the tracking for email 1 2 3, and domain B to be the tracking for 4,5,6. I understand I can do it in bulk… but with the # of accounts I have it can be a bit time consuming.