it would be possible to do this if i allow you to add characters to the fonts and then the mod can substitute the inline image in when you send that character code. This also helps keep the computational cost of manipulating the strings down.

That seems unnecessarily complicated.
Looking at the code for <color>, it's already allocating quite a lot every draw frame because of that regex splitting, it needs a redesign to read only without allocating any strings until it reaches a supported tag's value.

yes, which is why i'm avoiding adding additional tags right now.

Since it was redesigned, what about these inline sprites? :P

Still thinking this over :P

Well you can add inline sprites now via the custom font support. You can add them to existing fonts too by adding a character to the white or monospace font.