@MarcH I'm putting your name on this one:
Yesterday I was working with @Cedric via WebEx and we were building a macro together. We were making several field substitutions and and Cedric stated the obvious, "Alteryx should make this easier".
Contains([Field_X],"XYZ")
He would double click [Field_X] and the result is a partial selection: [Field_X]. The brackets don't get selected.
I'm sure that there is a good explanation for why this happens, it just doesn't make the UX wonderful.
Cheers,
Mark