0027, 02BC, 2019, or a new character?

[Christoph Päper via Unicode]

Michael Everson:
> Why on earth would they use Ch and Sh when 1) C isn’t used by itself
> and 2) if you’re using Ǵǵ you may as well use Çç Şş.

I would have argued in favor of digraphs for G' and N' as well if there already was a decision for Ch and Sh. 

Many European orthographies use the digraph Qu although the letter Q does not occur otherwise.