Beyond a good work around, this is 75% of the way to the canonical Lambda Calculus implementation that Bubble (cough-ahem @emmanuel) would need to adopt to enable parenthetical expressions. Long story short Bubble needs to implement a general
Bubble Expression action.
Much like Bubble’s existing arbitrary data sources, this action would raise a dialog with a drop-down input that lists all the data types available in the app, and a Bubble expression editor. By having the developer choose the type of the resulting data this would allow Bubble engineers to apply their strong type checking system to provide type mismatch warnings in the IDE. The result of this action would then be available through the usual
Result of Step N operator.