Well I think the difficulty spread is pretty make sense to me because it goes from single to double, I mean as you can see in MX diff I'm using double to emphasize all kick and snare sound, meanwhile in HD diff I'm using single notes for them. it'll be questionable if it goes from single to triple which is quite retarded. Besides, the sr gap between those 2 diffs is just 1.12, which is not really bad for a difficulty gap right?
I know my HD pattern looks 'empty' compared with the MX one but there's a reason behind it. At first I was using double notes for layering the snare sound but it didn't work really well in this fast bpm. And also I don't want to ignore the 1/4s kick because that's what makes the song unique/special and fun to play so I keep layering them through the entire chart. But with all of those double notes, it makes the pattern become really dense and the sr was over 3.5* which is not appropriate for a HD diff so I decided to nerf them with single notes instead. It plays better and flows nicely with single notes and the sr is not too high and not too low for a HD.