Author of the tool here. Thank you very much for your detailed review. I appreciate the time and effort to go through to provide elaborate critique.
- The eyebrow one is a straight bug and I'm glad you caught it.
- Base range 8 to 32 is excessive, agree.
- Per-element overrides existing doesn't help, if the thing that loads first establishes uniformity. I'll fix this too
- About the the tracking, you're right that flat -0.02em across h1 to h6 is wrong. I think the proper fix is to make it size-aware
- I'll fix and curate the pairs more, and aim for half of what I have now.