Should buttons tints affect children entities too?
Currently, the tints on the button component do not affect children (e.g the text) which seems odd. This can make fading the button on hover, click etc difficult.

Example here when clicking: https://playcanvas.com/editor/scene/1034629
I think that the children should be affected like the Image Element Group Type.
Both paths are valid, I think during discussion of affecting children or not, we choose not to, which is similar the way background-color works in CSS.
There are situations where tinting/alpha propagation would be useful, as well as cases where it is not. Although propagating values down, can complicate internals.
I think tinting on the image element shouldn't affect children (unless it's a group type). That makes sense to me.
Buttons I argue it should as you are tinting the whole button element which would include it's children
Some hidden rules of propagating/non propagating, would probably confuse users. But having a checkbox "propagate" for certain properties, probably would make sense.
This feature would be useful for me too.