Of course, Kopi was aware of what Irregular meant by Shanti.
In the Elements-related gift, the basic elements are common, and it was an advantage since Awakeners on a higher ranking could provide higher insights for future aspirants with similar gifts.
Therefore, despite it being common, it was a desired gift to obtain.
However, the rarer it was, the rarer the aspirants to gain knowledge about their gifts, and thus, the higher the difficulty of ascension without building a perfect foundation.
This was the case for the Ice element.
Although Ice elements were common in the Renazaille Country, it didn't mean they were willing to pass on the knowledge, especially in-depth, about the Ice element.
Therefore, it was why the Ice element didn't belong to the common elements.
Consequently, Kopi became irregular because of it.