copy+paste really isn't a bad thing at all and whoever it was who convinced people that it always is needs to get their ass whooped lmao. it can be a problem if you use it excessively, but there are definitely ways to use it that simply make charting more efficient.
the vast majority of music like this can be thought of as having sections: intros, bridges, verses, chorus, etc. these sections will very often have elements that are not are only similar, but are literally the same. in this sense, copy+paste isn't being lazy, it's being consistent. if the vocals were charted with the same long notes in each difficulty, but then you layered in the other instruments differently to account for how hard patterns are across difficulties, it'd honestly be weird if anyone were to call that out as wrong lol.
pitch relevancy isn't a hard rule, if you're strict when you use it, it makes for awkward patterns. the more you layer, the looser you can be with it. you can think of it more generally like "the chart moves from left to right when the pitch increases and vice versa." for example, let's say you've only charted the vocals using single long notes, and they're super accurate in terms of pitch relevancy. then you go back and start layering in kicks, then hi-hats, then snares, etc. you find that if you keep the vocal patterns the same, the drums force some nasty bracket patterns. you can move some of the notes around to get rid of the nasty brackets, and it still feels like you've maintained pr.
my biggest recommendation would be to chart by jumping around between various sections and put more effort into keeping things consistent. not sure how to chart the ending stream section right now lol, I'll look at it again today