How to write an EXR multilayer

I was trying to write multiple layers in one file, and according to Natron it is possible:
outputChannels_label

But I can’t find the option “All” to write all layers:
outputChannels_options

I tried checking “All planes” but I can see it does a completely different thing.

So I was wondering if it’s actually possible to write an EXR multilayer with multiple layers inside, because this would be useful not for final compositing but for correcting 3D render files (replacing wrong layers) without the need of rendering all again.