i think you'll find that 'celtic' doesn't come as a discrete set of styles but is scattered across various xtra paks and updates. you might consider waiting for the december 2021 pak to be put on sale at special prices and upgrade to the ultrapak which gives you everything

the usual advice on the forum is to buy the best pak you can afford as that stops you getting n/a when you choose a style

and although you have specific requirements, you might find it better to buy everything - including styles you think you'll never need. its better value than picking and choosing and the musical choices you get open new creative vistas.

i use folk, country and pop styles and couldn't see myself ever using the jazz styles, but just recently i did................