there are two parts to the problem here:
- first, you need to translate the list of taxa from your source to a list of iNaturalist taxa. some of this is probably a manual task because your source may not match iNat taxonomy exactly. but assuming they do match exactly, i would probably do the translation by extracting the each list of taxa from your PDF and then uploading that (add batch) as a new iNaturalist list. once loaded, you can download your list, and the number in the URL field will be the iNat taxon ID. (you can also access a json version of the list, 200 taxa per page.)
- add your taxa to your project. to do this en masse, you’d probably have to do this via the API. the third point in this other post (https://forum.inaturalist.org/t/edit-project-breaks-entirely-for-project-with-undefined-user/30070/13) describes how to use the API to add a user to the project criteria. you would just need to adapt this to add taxa to the project.
so it’s definitely possible, but i guess you’d have to decide whether you think it would be faster to accomplish things using the process described above, or if you think it would be faster to just add everything manually.
i’ve thought about making a script that would basically sync up a project’s include and exclude taxon criteria based on two iNat lists, but i sort of fear the unintended consequences of making that sort of functionality too readily available to the masses.