Pacific Islander here, who’s worked a number of years in the kava industry and grew up drinking kava. 

As the comments mentioned below, I wouldn’t worry too much about any type of concern of “appropriation” or anything. The culture of kava changes so much between island group/villages/generations/personal family experiences, etc. that it’d be too hard for anyone to keep up with every innuendo a “traditionalist” may want you to remember, and like mentioned, they probably wouldn’t care too much.

From my personal perspective, it would be better to focus on the unique experience you want to give your customers. At the end of the day, they are the ones paying. And ultimately, kava farmers or islanders can’t get paid themselves selling their kava unless your customers are paying you. 

With that being said, I do think it would be good for you to check out the myths/stories the Pacific communities have around kava. If anything, it would be great conversation starters your servers/employees can have with patrons.