Site add limit with free account

Since the question is similar to this one, kindly read more information about here:

Due to importing DNS records and limits per domain, here is an article:
https://support.cloudflare.com/hc/en-us/articles/200168856-Importing-and-exporting-DNS-records

@michael could know the answer so far, as he could suggest you an idea for your topic regarding the import and limits.