...cryptomatte while also using less space for channels that don't need full float
If keying off the channel name isn't ideal, maybe `rp` could have some sort of `type` attribute that could be used to decide what gets full float.
The current limitations of this are in the compositor. I have been unable to find a channel name in `OutputOpenExrMultiLayerOperation` to use.
I don't think this needs any user interface. The documentation on Cryptomatte should warn that those passes from a render are always full float