Yeah, the kinetic text tags are a displayable being shown as part of an overall text displayable, but that text displayable doesn't know to pass it's style information down to the kinetic text tag's text. My solution to this was defining a style with all the properties you want, and then using the {=style} tag (https://www.renpy.org/doc/html/text.html#style-text-tags) INSIDE the kinetic text tag to carry that information in. While going through the text it's given, my text tags will try to keep track of other tags inside it and apply them to their text. So you'd want to do something like
style narr_text_style:
color "#fff"
outlines [(2, "#000000")]
size 1900
font "fonts/DisgustingBehavior-AZrA.ttf"
"{sc=10}{=narr_text_style}{outlines}No! You just don't want me to be happy!{/sc}"Not sure the style tag applies all of that attributes, especially outlines, or if that will necessarily work entirely. Though that's the general way I made it work.
While looking into this though I did learn that renpy now has some of this stuff built in. https://www.renpy.org/doc/html/textshaders.html So if it's not working it might be worth using their jitter instead.