I haven't asked my doctor yet. I usually do an annual checkup mid-year, and I'll bring it up then. I should have more observations, too, which might help the discussion. My resting heart rate seems to be lower since I've been checking it, and my active rate might come down, too.
I agree I might be an edge case. The articles I've read say things like "220 - your age _but everyone is different_." So yeah, I might be right on the money despite being 10% above typical. For now, the HRM is helping me gauge how I feel against a number. Feeling pretty exhausted? Yep, look, I'm up at 182 bpm. I need to slow down if I want to keep going. Four miles from the car. Should I keep going? I feel good, and yep, I'm at 168 bpm. I'll push on another mile.
I'll see how it goes through the spring. I've thought about looking for a running coach, someone who can help me understand numbers and train better. There is so much I'm still learning, but eventually I'm going to hit my ability to understand how to do better.