Yes maybe the orange zest would work better. I think the original recipe had a flamed zest, but I didn't dare try it!
I'm in the same situation with eggs, I don't have many yolk-only recipes. I do make hummus a lot though, so I have plenty of aquafaba.
It is not exactly as smooth as egg white, but it still works well for me. At least for sour cocktail, I'm not sure how well it would work for a fizz. It is easier to measure too, so the amount of resulting foam can easily be adjusted. I also have some vegan friends so it is a nice bonus!
Oh, kimchi butter noodles sound amazing! Definitely trying out that soon. Thanks for the ideas!