NOTE: The proposed changes/questions aren't directed at every champion and not even necessarily many at all. The examples given here are purely examples and not my opinion on a champion being OP/UP or anything of that nature.
The restrictions I'm specifically talking about is how whenever champion levels up a scaling ability, it always has a set amount that it scales. For example, Gangplank's Parley scales by 35 physical damage every time you level it up (20/45/70/95/120 + 100%AD). However, I'm asking from a designer's point of view, whether it's necessary for an ability to always scale up by the same amount each time you level it up?
I ask this because of nerfs/buffs.
Sometimes a champion's ability simply scales too much or too little at a certain part of the game. Would it not be easier to simply have abilities scale by exactly how much (or as close as possible) is needed for it to be balanced at that point in the game rather than it always having to be a set amount? If an ability scales by 50 magic damage each level, but around midgame this starts to be a bit too much power, couldn't you have it so it scales less, like by 30 magic damage, in the higher levels or even just one of the levels, rather than nerf the entire abilities scaling and therefore also that ability/champion's early game power (which might not be necessary but is an inevitable/necessary result for them to be balanced around midgame)
Though it'd be harder for newcomers to learn certain champions, it seems like some abilities/champions would be much easier to balance for you guys if you simply got rid of this, as I call it, designer's restriction. Plus, now that LoL is a legitimate sport, balance should really be the main objective. After all, no sports are easy to learn but they're all difficult to master, as LoL currently is, but it seems like this 'design restriction' simply makes it much more difficult on you guys as well as the champion purely so it's easier for people to learn the game which shouldn't be a necessity over balance now that LoL is basically a sport.
In every other sport the only things that determine a winner is the player's skills but in LoL we also rely on the balance of the champions, which I believe could be in some cases much easier to resolve without this restriction. I believe we need to make the game as balanced as possible ASAP. Yes, of course we'll still always need to re-balance some things in patches but I believe there should and could be much less to do with champion re-balancing (especially the ones that get multiple nerfs/buffs/both) without this restriction.
I actually DON'T value linear-only scaling for the reasons you mention. I think there are issues that exist because of this, and the benefits of clarity are so minor than I think they take a back seat to good pacing and balance here.
You'll probably see more non-linear scaling arrive in balance when we think it can fix the problem. It's not a silver bullet, of course, but I think a valuable tool (ESPECIALLY on ults since you can predict early- mid- and late-game based on that) to us to use.