Test my beta version of WishList linked in the 1st sticky comment of the addon, lower section "Beta".
https://www.esoui.com/downloads/info....html#comments
You need to manually install it as described there (watch the zip file contents -> only extract the subfolder WishList not Wishlist-master!).
I've finished adding context menus and visible markers at the Wishlist, as well as context menus at the Set item collection book headline (collapsable set name) and single pieces (set items).
It currently is able to add/remove all unknown/known items of a set. But not dependend on the curernt zone. Still working on a mapping but this will need some time, so one could add missing items directly to the WishList if you select a zone from a list e.g. -> WishList UI and/or Set item collection book's "Zone list" at the left (context menu).
There currently is no mapping between the zone name in the set item collection list and the zoneId which I'd need... So I first need to create such a mapping within LibSets.
Thanks for your feedback INSIDE THE WISHLIST addon comments, not here.