How can I specify an offset for all map markers?

[steveneal]

We are using pin shaped markers and need to offset their center to make them appear in the correct position.

I've created a symbol layer using the following properties:

SymbolLayerProperties(
    iconSize: 1,
    iconOffset: [0, -24]
)

but the iconOffset property seems to be ignored, and the pins always appear in the same position.

I can see no uses of this property in the example project.

Is this an unimplemented feature or am I doing something wrong?

Thanks.