@KimC,
While it is true that you do have to create new measures, I have a trick for you that I am using with card visuals that display aggregate measures that I have successfully tested with your situation. I usually use this technique to force a 0 to display instead of “(blank)” on cards, but it works just as well for your needs.
The important point is that you do not need to duplicate the measures, just create a new measure that divides the desired measure by 1000. This leaves with you with only one DAX statement containing your measure code so you only have to maintain the calculation in one spot. The second measure only formats the primary measure.
Here you can see the DAX I used for the formatting measure, which uses Sam’s measure branching technique. Note that I set the decimal precision to 1 even though the format is $ English which has a precision of 2 by default.

And here is the primary measure and formatting measure side by side in a table.

I put all such measures into their own measure group to make it easy to distinguish the formatting measures from the primary measures.
Hope this helps!