Problem 1: this page states that tags for GPX traces are case sensitive.
Problem 2: partial tag names search is not supported, so that these would theoretically produce different results, multiplied by the case variations:
yellowstone, yellow stone, yellowstone np, yellowstone national park
Is there a place to request to revisit this feature?
Also, if there was automatic automatic suggestion for tags, that would cleanup all the variations:
either offer somethere based on partially typed name,
or first upload GPX, and then show a prompt: here are previously used tags in that general area.