I've no issue paying for two different accounts (both seperate emails), one NA and one EU for over a year. NA account I pay for with my credit card set to reoccurring, and my EU account I pay with crysta manually each month (bought crysta with paypal because of conversion).

If you want to avoid possible complications then it's probably a good idea to pay your second account's sub with crysta and on a seperate business day so you don't get two similiar charges in a day.