now that the dynamic life list exists, it should be possible to create a browser extension that uses the data from the underlying API route (GET /v1/observations/taxonomy) to modify / decorate the taxonomy tree with information about whether or not you’ve seen the any given taxon and maybe also how many observations you have for each taxon.
@sessilefielder authored an existing extension that, among other things, can modify the top of the taxon page to tell you how many observations you have for that taxon. so i think it would make sense to add this sort of requested functionality to that existing extension.
not directly related, but i created something a while back that will parse that life list data a little bit to make it a little more friendly for making things like sunburst charts and that sort of thing…
EDIT: oh, and i forgot to mention that you could theoretically use /v1/observations/taxonomy to create life lists for, say, projects and places instead of users, or you could add other filter criteria that are not available in the standard dynamic life list interface (as long as the set of taxa that you return isn’t too massive).