Good idea, noted for team, but unlikely to redesign this in short term. Definitely not ideal for non english grammar, or edge cases such as the parenthesis you mention above.
A current workaround is that you can press escape to cancel the Emoji menu. This removes the menu quickly without slowing down typing:
Sorry to insist but I used over two hundred software and I never had such a big issue when just writing (with the rules of my language). And by the way in ten of thousand pages written, I never used one single emoji (I really dislike them).
This is particularly irritation as for an outliner, I write lots of lists. When working dayli with Tana, I had about 30 to 50 emojis inserted involuntarily.
I noted your advice, but using it makes a new writing habit that I kept with other software than Tana, and provoking other issues!
I quick fix could be another shortcut, as "::" for instance.
Other quick fix, allow personalization of the emoji panel shortcut.