If you want to fix your slider issue, pay more attention to the sliders while you focus on learning.
For slider heavy maps with velocity changes around 4-5* range, you're describing like, a majority of tech maps around the range, when it comes to examples, i am not going to be very helpful on this, but try:
Silentroom - Nhelv
Akira Complex - Ether Strike
Camellia vs Akira Complex - Railgun Roulette
Camellia - syzygia
Pretty much every camellia map
I also just remembered that some alt maps are also slider heavy in that range, mostly with consistent SV but uses higher SV, but i found a monstrata map in progress where it has changes
beatmapsets/801747
And uh for more i think you should wait for either other responses(you can retitle your title to indicate that you're looking for slider maps with velocity changes)