While internal difficulty spikes are completely okay in my book, I think it should be changed around a bit, mostly because the hand motions for the latter half of the extreme part(particularly this 02:16:948 (1,2,3,4,1,2,3,4,1,2,3) - ) is very awkward to play and requires quite wonky hand movement(and very precise too, given the high spacing). although, i don't think you should nerf the pattern too much - it really makes the map worthwhile and memorable, which i think is great. i seem to be in the minority here, though.
a couple other notes on small things that I found to be weird in the map:
01:26:220 (1) - put this on the sliderstart of the (3) before it, to continue the back and forth thing. quite minor, but i don't think it makes sense as is.
02:04:948 (1,2) - i understand you'd want to emphasise the vocals and the start of the solo, but please don't make 1/4 jumps like this.
02:19:948 (1) - this one note is quite underwhelming since it breaks the upbeat clap pattern. considering it's the final part of the solo it's more noticeable.
02:22:675 (4) - please adjust this so that it flows better coming out of (3).
02:44:766 (5,6,7,8) - these make little sense considering the music. i'd expect separate stacks where the music change notes (so it'd go like 4-2-1-1)
02:49:130 (1,2) - ^ likewise, these two should be stacked