why not just use a canvas shader? so we dont have to apply the fx from C2? having it inside directly.
those extra characters look interesting the little heart, that type of extra stuff wold be actually awesome to have.
image results of using Adjust HSL FX
The issue is having multiple colors/font weights in the same text run, which sprite fonts don't currently support. 
Ashley mentioned a markup language to achieve this, and as an example Unity uses a system mostly similar to HTML and I've found it to be a good solution. It has an option to generate a separate texture atlas for every required font weight, and handles them in a way comparable to having multiple animation frames in C2 - a list of assigned images, basically. It'd be nice to see a similar system in C2 and would open up a lot of interesting possibilities with fonts, even if for the time being we have to generate each texture atlas outside of C2.