Irregular spacing is a feature, not a bug, unless you're playing Schönberg and friends, because being able to quickly separate thirds, fourths and fifths is much more important than being able to grab octaves and even more important than identifying individual notes.

Your brain anyway doesn't have to work on "it's on a line therefore it's one of C D E F# G# A#", it very quickly learns to work on "it's on adjacent lines therefore it's a third apart" when you read sheet music. Two notes both on lines or both on spaces are part of a triad; "two notes very far apart, one on a line and one on a space" is almost always an octave, and you can grab that intuitively in standard music notation even without reading the two notes one by one; whereas smaller intervals are simply too far apart on isomorphic notation.

Same for understanding when your scale is changing or you're deviating from the normal fingerings (key signature vs. inline accidentals). And all this ignores the fact that G# and Ab aren't even played the same on some instruments, at least at an advanced level, and chromatic notation cannot capture that.

The problem is "a third apart" means different things depending on where on the diatonic scale that third is. What I actually care about is how many MIDI note numbers apart it is, because that's what corresponds to the finger positions on the instrument.

>G# and Ab aren't even played the same on some instruments

Seeing as we've freed up the sharp and flat symbols, we can repurpose them to mean adjustments by whichever comma is relevant.

Maybe you read sheet music different than how I do, but when I play euphonium or trombone, I translate from note position+features to finger+mouth position without needing to think about the note letter. More like, "I see the note located here with an accidental feature in the context of the clef and key signature therefore I use this finger position and mouth position". I would love to simplify it down to "it's located here therefore I use this finger position and mouth position".

Keep the accidentals to notate alternate finger positions for enharmonics (and microtones), but eliminate the global variables, the clefs and key signature. Heck, keep the key signature to reduce the noise of alternate fingering symbols, but PLEASE eliminate the clefs. I would also love to play treble clefs at the same sight-reading speed as bass clefs. Also, staff notation should visually repeat every octave, but it doesn't.