Clarification on 'up to' abilities?

Magrailothos

There are quite a few characters who get 'up to' a certain amount of perfect block, damage, armour or regeneration based on different factors; such as Captain America WW2, Hulk, Hulkbuster and Groot. There are probably more, too.

Is there any record anywhere of how these abilities work in more detail? Like does Cap get half his bonus for opponents with one buff, 75% with two buffs, etc? Does Hulkbuster's armour increase directly proportionately with missing health (40% armour with 40% missing health), or is it an inverse logarithmic scale like Diminishing Returns (Approx 75% armour with 40% missing health)? It would just be nice to understand this a bit more. I know I may be a bit of a maths geek; but playing this game, I'm unlikely to be the only one!

Sungj

I doubt any mods could give you an answer if you really want to figure it out measure out a champions health bar and see how much damage you take at certain thresholds thats probably the only way.

HoidCosmere

The wording is vague so you can tell when it isn't working right.