If you are managing more than one account on a regular basis it is much easier to manage multiple individual Google Ads accounts within a single Google Ads Manager (MCC) account. This will then allow you to sign up for either the PPCnerd Manager or Enterprise Plan (depending on whether your MCC has more or less than 50 linked client accounts) and any deployed automation scripts can run across all of the linked client accounts within an MCC.
However if it is a company/business requirement to keep individual Google Ads accounts not linked to a Google Ads Manager account, then it is perfectly ok to sign up to multiple PPCnerd Individual Plans to automate the workflows in each of the individual Google Ads account.