macdeployqt has no way to build a cross compiled thin library

For conda-forge Qt 6 is built thin, i.e. either x86 or arm64, but not both. This includes macdeployqt.

However, the host systems for building conda-forge packages are only available as x86.

There needs to be a way to run macdeployqt on x86 and have it copy files appropriate for arm64, i.e. cross compiling. The frameworks seem to be copied properly; but the plug-ins are copied from the host architecture.

One option is to be able to specify something like -qtpath to macdeployqt for indicating the desired library sources.

If there is another way to do this, please tell me! Otherwise, this seems like a lacking feature that makes it impossible to use macdeployqt in these cross compiling situations.