Tempo markings should be linked to the chord or rest they were created on, not to fixed positions
Tempo markings can't be copy-pasted along with the music they belong to. This makes no sense.
Tempo markings should be linked to the chords or rests they were created with reference to (ie. the chord or the rest the user selected before adding the tempo marking), not to their position (measure # / beat #) in the score.