interesting spread, it's unusual to see such dense normal/hard diffs lol. i'm curious what other people think about the diffnames because of that (maybe ask 2nd bn for an opinion?)
The use of 3/4 gaps, the 6-long chains of 1/2 circles (#3804123), and the 1.5x distance snap are all fair arguments - I doubt there would be much disagreement if the Normal were renamed to Advanced - but ultimately, it's down to whether it "plays like" a Normal, i.e.: would a Normal-level player be able to play it?
^^ for the Normal diff "1/4 rhythms can be slowly introduced. Closer to 120 BPM, that would mean very rare 1/4 rhythms in chains of 2 objects or so." https://osu.ppy.sh/wiki/en/Ranking_criteria/Scaling_BPM
Having some 3/4 breaks in rhythm should be comparably easier than occasional active 1/4, and since it's consistently used throughout the diff that makes the pattern recognition easier for newer players.
However I did make a post at #4114954 for some minor density changes for two sections.