Very cool. Personally I'm not particularly invested in DPI, but it's your call as the person scanning and translating. Interesting to compare your old version and this new version.
Sidenote: I'm not super confident in my Japanese, but a part of me suspects that the 「カラーン コローン / カラ~ン カラ~ン」 sound effects in this chapter are a representation of a school bell. In manga, I'm more familiar with a more common 「
キンコーン カンコーン」 (which Wakaki has used before) as representation of the sound, but the way it's framed as an exterior shot at the end of the school day and phonetic resemblance to the standard sound makes me think it could be a variant spelling.
I tried looking up youtube videos of
Japanese school chimes to see if there's anything that sounds deeper, but I can't really tell myself. This
Japanese youtube video actually mentions a "karan karan karan" sound use back when they had physical school bells that had to be rung, so I'm genuinely unsure.