Measure format: Currency + auto decimal?

I have several cards displaying measures like SUM(sales) and their value can range from billions (unfiltered) to millions after filtering.

When the decimal point is set to auto, it automatically adjusts the value from say 1.52bn to 582M i.e. 2 decimal places when in billions and none when in millions. Perfect.

However, when I switch to using a currency format the auto decimal point is unavailable and so it must always have a fixed number of decimal places. 
If I set it to 0dp then I will get 2bn overall which is not what I want. If I set it to 2dp then I will have 582.54M when it's filtered which is equally not what I want.

Is there any way to specify a currency and still have automatic decimal places in Power BI Measures?

p.s. I've tried conditionally rounding the value to 0 dp when it is less than a billion but it still managed to display two decimal places. Cheeky Power BI remembering decimal places I think.

Thanks