Flex Repeater - How can I get the instance number to use in a binding within that instance?

[Transistor]

@Craig_Rathbone, @nminchin, see my answer to Perspective Text Field Numeric Keypad - #41 by Transistor.
There is a secret "index" parameter passed to each instance of the flex repeater and you can use this for a variety of purposes.

Perspective - Flex Repeater | Ignition User Manual