I shouldn't need to say this, but... READ. THE. DAMN. CODE. The ISU communication you're looking for is here:
https://www.isu.org/figure-skating/rules/fsk-communications/24665-isu-communication-2334/file
Spins have 11 possible level features (13 for a layback), only one of which is holding the same position for 8 revolutions. The reason so many skaters use the same level features is simply that some of them are easier than others, and there's really no benefit to using a harder feature if you can get a level 4 with easier ones. Now, this said, if the ISU wanted to split the level features for spins into tiers one, two and three depending on the difficulty, and have, say, a tier three feature be worth X2 tier one features to encourage use of more difficult features, I wouldn't complain. However, this would make judging a lot more complicated, so I doubt that's going to happen.
Now, what I would actually like to see:
1. A couple more level features added for step sequences, so that skaters can pick and choose which features to use based on their strengths in order to get a level 4 the same way that they can with spins (and so that a few will ditch the "Use of body movements for at least 1/3 of the pattern" feature)
2. An increase in base value for level 3 and 4 spins and step sequences - the difference in base value between triple and quadruple jumps is large enough that doing a triple when your opponent does a quad can take you off of the podium, but the difference between a level 3 and 4 spin or steps is negligible, and there should be a bigger point gap between each level.
3. An increase in PCS factoring, particularly for the ladies, since average/median TES has increased significantly since it was set
4. More clearly defined PCS bullets, more akin to GOE bullets
5. Level 5 spins and steps please, since some lunatics are now talking about quints and all