✨ Feature Request

Compress auxilary coordinates and ancillary variables of the same shape as the Cube data payload.

Motivation

Reported by @pasc85. Saving a status flag - which can either be 0 or 1 - is producing an unnecessarily large file. this is an obvious case for compression since the array will have a large shape, but could in theory be represented using a single bit

Additional context

• May be extended to cope with further metadata, such as meshes, but this is considered out of scope for this initial use case.