If the panels are going to stay the same going forward (technical panel and one GOE/PCS panel of judges), then I don't think a -5 to +5 scale is going to do any good. The judges are going to have to be even more meticulous about whether they should score element A a +2 or a +3, and so on.
The bullet point criteria for how to earn a +1, +2, and +3 also should definitely be condensed.
1) unexpected / creative / difficult entry
2) clear recognizable (creative, interesting, original for jump preceded by steps/movements of
the Short Program) steps/free skating movements immediately preceding element
3) varied position in the air / delay in rotation
4) good height and distance
5) good extension on landing / creative exit
6) good flow from entry to exit including jump combinations / sequences
7) effortless throughout
8) element matched to the musical structure
This is straight from the ISU. In order for a +3 to be considered on any jump or jumping pass, a minimum of 6 of these features must be achieved (and 4 for a +2, 2 for a +1).
But for starters, if you have #1, you probably have #2.
#6 and #7 could also be combined (if you have one, you probably are going to have the other). And even a bit of #5 could be thrown in with these.
I already mentioned #8 being somewhat silly and extremely subjective, because if a skater has slow music without a really clear beat, who is to say they did or did not match the structure? That one should definitely be gone and more impacted in what would be the presentation part of PCS.
I think the GOE of a jump should be based on the entry, the air position and height/distance, and then the exit extension and flow. All three of those should simply warrant a +3 and there's not too much room for open interpretation. In the short program, the judges are still throwing out huge GOEs for solo quadruple jumps without any steps at all. So remove the 'steps into the solo jump' requirement and just reward it with the GOE, if they do accomplish it (ie. you can't get a +3 unless you do some kind of steps or creative movements into the jump)
A jump done on the wrong edge should never get more than a -1 GOE in my opinion, even if it's the ! call. Many years ago I thought technical panels should really just call the jump as it is attempted (the edge it takes off), and if you can't do a flip or Lutz the right way, you have to find another way to earn points. It's silly to give skaters the majority of the credit for a third (or even fourth) attempt at the same exact jump but completely void the element if it were a toe loop, Salchow, or loop. JMO.
There needs to be a way to separate the panels, but giving the technical panel the duty of assigning GOE's on top of element levels gives three people too much power IMO. With a really clear-cut definition of what is needed for a +3 rather than these lax criteria that overlap each other, there isn't really a need for a panel of 9 or however many judges to assign the GOE. 5 would probably even suffice. A panel of 7 watching the skating skills and presentation of the program may also work since they are not focused on the elements. So you'd require 12 judges per event, and I'd even say that their positions in the short and long segments could be drawn randomly- so they may judge TES one day and PCS the next.
But in the end, just like in the ordinal system, they will find a way to boost or lower skaters' scores if they really want to, as has been addressed by a few posters. But it may not be as much of a case of
wanting to do so versus having to focus so closely on the program and then at the end thinking 'Well the audience reaction is great, the skater did pretty well and skates late in the day, so I think I'll give X score for PCS since I wasn't paying as much attention as I should'.
One thing that is better about IJS and the single biggest reason I prefer it over ordinals is that if Skater A has a bad day in the short program, they can beat Skater B by a large margin in the long program and win overall. In 6.0, Skater A's bad short program made it a nearly impossible task, even if they were a 5.9/6.0 on the free skate and Skater B (who was good enough for 2nd in said free skate) only earned a 5.2/5.5.