There are 3 things that stand out to me that I will find it difficult to agree with, all of fairly similar nature.
CL - Not being able to use the bumper platform to the right of the jump.
RiRo - Not being able to use the right-hand lane after the jump.
LP - Not being able to use the bumper plate after the jump.
All of these are conspicuously intentional and add to the variety of the course. They're so intentional I actually feel that if we can't use these with a clear conscience, we shouldn't boost over grass like it's the most natural thing to do either.
I'm no MK:SC track editor, but these are there as a convenient conventional methods of skipping track. Aforementioned tracks lose some of their uniqueness in our attempt of making it "purely about racing" (Why does that consistently have to be about driving on the road. Can't it also be about making clever use of what's there as part of the (broken record alert) conventional driving?
I'd understand if we're taking a "moral hardline" so to speak against ways of breaking the game, and making it shorter, but do we really have go to these lengths to do it? (I mean, I'd understand banning all forms of lakitu skips unaided wallskips and tricking since those don't utilise a lot of the driving we call the quintessence of kart, but banning certain routes and enhancements because you travel too far in the air? Is it allowed on RaRo because it's so consistently occuring? Or because it's so difficult that anyone mustering it deserves the benefit it gives? (By this logic, the SG jump would be allowed, so this might not be it, but it's a fair question.)
Removing it in CL takes away what's really the only element of difficulty in the track. This one boggles me the most. Are we allowed to cut over the wall to the right of the first jump but not allowed to land on the platform to extend the jump because it cuts too much of the straight? Are we not allowed to skip the wall at all?
Removing it in RiRo breaks the flow and makes me feel stupid for not using such an obviously advantageous route that takes so little effort. (I'm guessing the latter is the reason behind banning it.) It's so intentional and widely used that to me it feels like banning the bumper skip in CCI.
Removing it in LP means ignoring the obvious and intentional for an almost stupidly conservative approach. The built in booster before the jump is there for the sole purpose of helping you make the jump to the plate with the conventional driving.
People who have not played this game are going to watch ghosts of me using these paths and conclude I'm stupid. *starts crying*

Thank You for taking your time with the Non-SC rules.
Andreas