In general I think the doc is really well-written and mostly what I had in mind as well.
I commented on GitHub with a list of things from my own notes I would like to see added before merging, including some definitions, technical requirements for making a species PR, and a list of examples with good and bad traits for reference (some from previously declined species).
Yeah personally I also see no issues past what I have already listed in my review. My main issue is the fact we should not list species by name in the doc itself as designs can change and be improved upon, or allow any species to bypass those requirements.
If those parts are addressed I think the doc will be alright.