Well.. yes, this does not look to bad! o)
From experience there are a lot of special cases with button codes and things, I don't really wanna hate on them or the new evaluator functionality, you can surely manage the different syntax at some point, but the challenges may be in the unexpected, like here.
I read some more on the evaluators, if they are quicker than using jscript for generating simple column values e.g., why not! Every language and syntax can be a tool, and there's always the right and the wrong tool for a job.
@Jon
When reading about Evaluators, I had the impression these are also used internally for handling GUI updates / conditions etc.? Is it some kind of functionality that already existed in some state and you decided to make it available to the user as well? Or is this a complete new invention for the user in v13?