I feel silly now, as I somehow never recalled reading about alternative fingerings (especially the 13 for Eb) on the threads I read on the forum back then. I know there are alternative fingerings, like 1+4 for Eb, 24 for E, but they sounded very stuffy and still rather sharp for me. So I assumed that it would be extremely hard to lip them all down adequately. Will keep trying and see how they turn out, especially the 13 for Eb!