As of the Layers Creation/Removal - this is being worked at right now, though this is not an easy task and these operations are absent in the majority of the PDF editors - thus we need to think through all of the details and logic. This is not a simple matter - so called Layers are a visual representation of the OCG/OCMD in the tree - that's all. The real deal are the physical Optional Content Groups that define the content and annotation visibility. The greatest task is to make this easy understandable and usable for users.
You can read more about those in the PDF Specification.
As for the ETA - not for the upcoming release, that's for sure - maybe the release after this.
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