Hi, there is no way currently to change the priority for each taxonomy term.
The priority value has always been misunderstood by most users. It’s not an indication of importance but a suggestion of the order in which URLs should be indexed. And even then, there is no real life case where there would be such a huge amount of new (!) URLs that spiders would take so long that there is any need to prioritize them.
In fact, the priority and changefreq values have not had any real impact since a long time. See https://www.seroundtable.com/google-priority-change-frequency-xml-sitemap-20273.html
As such, they are planned for removal because the lastmod value is a complete replacement of both. The search spiders will base their own priority on that value, not on whatever priority is assigned by the webmaster…
Hope that helps ??