Singles: bonus for +3Lo and +Eu+3F combo. Lower the value of sequences, but not as low as pre-2018. More creative jump combinations. The handbook list both of this as allowed combinations instead of sequences: (1) Listed jump + 1Eu + three turn on the same foot + Axel type jump and (2) Listed jump + one intended change of edge + Listed jump in the other rotational direction. But I don't see anyone competing at GP/Worlds/Europeans/4CC utilizing them
I like these.
If the values for doing those kinds of combos are worth more than doing a standard combination with the same number of revolutions, that would reward the difficulty with an appropriate number of points, I think more skaters would add those skills to their repertoire. They won't if the element is risky and only possible with doubles (or single axel) as the final jump because they're more likely to lose points for lower base value or lower quality than they are to gain points for creativity.
Also, for singles: more verified jumps. Why is Walley / Toe Walley not in the list?
It was already decided in the 1980s, with the introduction of the Zayak rule, that toe walley and toe loop would count as the same jump because there wasn't real difference in the way skaters were executing them especially as triples.
Walley wasn't included in the IJS scale of values because it is pretty much always performed as a single jump, which the ISU evidently wanted to keep as a transitional move that wouldn't block a jump box.
Personally, I think they could leave the single walley as an unlisted jump but add doubles and triples to the scale of values. If base value is commensurate with the difficulty, skaters would have an incentive to learn them
And apparently very long before IJS they used to compete Toeless Lutz and Inside Axel.
Those could also be added. They have pretty much always been done as singles and were not common in the pre-IJS television, pre-triple jump era -- I can't speak to earlier eras as I haven't seen many early performances and don't remember reading much about them. Inside axels were done but almost always as singles.
So again, I think the best approach would be to leave the singles as unlisted elements and add the doubles and triples to the scale of values, with appropriate base values.
I.e., doubles worth at least as much as a double axel, and triples (which we may not see for decades) at least as much as a triple axel.
Peggy Fleming used to do a 1 1/2 flip on purpose.
Yes, I have read about those going back to the 1930s when double jumps were still cutting edge especially for women, and seen them in other 1960s/early 70s jump sequences.