General rule about damage increases?

This is actually a pretty complex topic, and I've spent hundreds of hours of compulsive research to compile whatI know so far

Champed 3*s gain about 0.4 'levels' of ability damage for each champion level between 167 and 276 or so. After this is grows a bit and I haven't figured out the rate yet.

 MPQ rounds to the nearest whole number when determining rank 1 damage (or healing, or strike strength; any scaling number) and before multiplying for rank 2-5 values. So for the scaling value to increase the rank 1 value must increase by at least 1.

Using Deadpool's "Life of the Party" damage threshold as an example, its value increases by 2 each champion level. (Incidentally, so does GSBW Pistol and Hulk's rank 1 Clap damage). Whales! Whales! Whales! increases by 3 or 4 each champion level (3.6 per level on average) and A Little Off the Top by 2 or 3 (should be 2.92 on average).

Meanwhile, Luke Cage's "Unbreakable" protect tile increases only every 4 to 5 levels. The average increase per level, that I have calculated, is 0.24, so because the game rounds to whole numbers and only multiplies for ranks 2-5 AFTER rounding off the rank 1 value, it won't increase every level.

The "ability levels per champ level" for 4*s is more complicated, and additionally I have less data (as I have 16 4* champ levels total) but from what I can tell, 4* champ levels increase scaling ability values more and more the higher level you get. A fully championed 4* does about double ability damage compared to a level 270 4*

Hopefully that's still a coherent answer. If not, I apologize; if you have a specific ability you were curious about I can probably provide you with the expected scaling gains for 3* champ levels.