I’m not sure what you are saying here.
To tune a lever harp in the key of Eb means that when the levers are NOT engaged the strings are tuned as follows:
Eb F G Ab Bb C D Eb
It doesn’t mean tuning the C string to Eb. It means tuning the E string to Eb, the A string to Ab and the B string to Bb. All the other strings, including the C, are left tuned to natural.
Yes, the relative minor is C minor, but I don’t know anyone who thinks of it as tuning to C minor. Most people think of it in term of the Major scale.
But you are right, when tuned to Eb you need to raise the E, A and B levers in order to play in C Major.
Pedal harps are not tuned to C. Without the pedals engaged a double action pedal harp is tuned to Cb Major. That is all strings flatted. When you refer to how an instrument is tuned typically that refers to how the strings sound when they are “open”, without any mechanical or physical action taken to alter the string. No levers up, no pedals engaged, no fretting or Capos or anything like that.
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