Indirect tag in an expression binding?

[nminchin]

Indirect Tagging in Expression

This will work, but note that for performance you should really use two custom properties with indirect tag bindings, and do the sum in a single expression referencing those two custom properties. The tag() function can't be optimized the same way indirect tag bindings can, so it's a performance pitfall.

Indirect Tagging in Expression

Fixed that for you. Really, if you are using the tag() expression function in a User Interface binding, you are screwing up. Full stop. The only appropriate place to use the tag() expression function is to perform indirection within an expression tag. Nowhere else.

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