Orient Express - Cheap Chinese Rims / Wheels / Forks / Frames / Cranks / Etc

First interesting thing to come out of it is that I can produce the same power with a heart rate 10 bpm lower if I spin a lower gear faster (than a bigger gear span more slowly).

Did you do these efforts immediately after each other or with a gap between them? Are you aware of 'cardiac drift' when looking at your HR info?