Not sure if this feature would be useful, as the mapper would still need to manually count the number of notes, overall not saving much time. Also, for orchestral music, to have it truly perfectly timed you'd have to change bpm every note due to human error in playing. And even if the map was perfectly timed, the player's UR would still be high as the player can't predict all the little bpm changes.
p.s. if this is your first beatmap, I strongly do not recommend variable bpm music like classical stuff, because it's a pain the ass as you rightly said. Here's a map of the 3rd movement of the Moonlight Sonata, and as you can see the timeline is jam packed with red lines.
https://osu.ppy.sh/b/1101611
p.s. if this is your first beatmap, I strongly do not recommend variable bpm music like classical stuff, because it's a pain the ass as you rightly said. Here's a map of the 3rd movement of the Moonlight Sonata, and as you can see the timeline is jam packed with red lines.
https://osu.ppy.sh/b/1101611