For doing ratios and conversions, it would be helpful to dynamically update the column name for ease of reference. For example, doing a 6:1 conversion the user would enter in 6 in the property control and the "6" would show up on the Column Name (6:1). If the user changes to 2:1 it would update to (2:1).
I agree, and when building a value using an expression, having the ability to revise the column name based on the expression would be useful. For example, if I have an expression that compares sales vs last year, I'd like to call the column name "Sales vs Last Year." if I use a drop-down/propery to change the denominator to 2 years ago (sales / 2 years ago), I'd like to dynamically update the column name to "Sales vs 2 Yrs Ago."