Character addition request in EuroLatin keyboard

I see that the EuroLatin keyboard is currently the one listed for Zapotec languages. In some of the Zapotec languages in the southern Sierra region of Mexico (including ethnologue ztg) a couple characters are used that are not included in this keyboard, namely an underlined x and an underlined digraph ch. We would love to see these be added to that keyboard to make this keyboard functional for another group of Zapotecs. Can this happen?

I’ve created an issue here:
We will look into when/if we can do this.