I think a major problem with 4S is that he has to jump it straight after the 4Lz. It's hard to get himself together so quickly. Last season he even had problems with the quad toe after the quad lutz, while it was fine in the SP. But at least there are improvements with the 4Lz. Although the axis problem still rears its ugly head, albeit not to such an extent as before. It has been suggested that if he could jump it with a certain forward lean at the beginning, it will keep it from tilting backwards at the end. Although I am not sure it's that simple. He sometimes used to get this problem with his 4T when he first started doing it and eventually he managed to get on top of it. Of course his 4T isn't anywhere near as huge.
https://www.sports.ru/tribuna/blogs/ternovblogfk/1442944.html
On the subject of jump height, these Jump Statistics were posted in The Edge and I think are relevant enough to repost here. The tables at least are in English. Nothing unexpected, such as that Misha's 4Lz is the highest jump currently done by anyone and he is the highest jumper overall. I didn't realise before reading this that Misha's 3S was quite so high. Jin, Petrov, Brown, Zhou, Erokhov, and Samohin's 3S had to be measured from 1/2Lo combos, but of those I think only Samohin is likely to beat Misha's numbers for a solo/first in a combo 3S. 3Ts were taken from combos for all skaters, and here it is interesting that Misha's 3T is pretty low. I think British Eurosport commentators even commented on it once. His 3S in the 1/2Lo combo doesn't look particularly high either. But then Misha said in an interview that triples pretty much rotate themselves and require little vertical force for him. So he doesn't jump 3Lz or solo 3S this high on purpose, it just happens. The problem with 3Lo isn't in the height or rotation, he obviously has some trouble with the takeoff. And his 3F was huge just as his 3Lz when he actually jumped it. Such a pity about the edge problem.
As for the rotation speed numbers, there has been some debate on whether the measuring method was appropriate, but it's still interesting. Apparently the highest rotation Misha reaches on the quads/3A is on the 4S (they didn't measure rotation on triples). The height on it is also quite decent. The issue shouldn't be in the rotation, and indeed he seems to rotate it just fine. Of course one problem with Misha's technique is that he ideally needs even slightly more than enough room to rotate his jumps in the air - why would you learn differently if you jump high and rotate reasonably fast, I guess? Skaters who are not high jumpers, not fast rotators, or neither of those had to learn various "cheats". Misha on the other hand has trouble landing jumps even within the permitted 90 degree UR, he doesn't excessively prerotate, particularly on the lutz, and he also often delays rotation. But once it comes to quads it can complicate your life. And his takeoff problems usually lead to pops rather than underrotated/messy jumps. (It's almost like he is allergic to underrotation and rather make any other error rather than underrotate.)