I think that a request for a grammar book for the purposes of learning the language would be off-topic.
This is not because it is a single-language question, nor because it could lead to a list of answers (although I do think that asking such a question could prompt a list of subjective responses, because even given your specific criteria, people are still going to have individual tastes in textbook-type materials).
It's because the question is less aligned with the discipline of linguistics, and more aligned with the related but separate discipline of applied linguistics, which is concerned with language teaching and learning rather than the initial linguistic description and analysis. The study of Ancient Greek also often falls under historical/classical studies, as many universities combine it with these sorts of courses, so people in these fields would probably also have good recommendations.
A grammar for teaching/learning a language can be quite a different thing to the types of linguistic descriptions of a language that are also called grammars. For anyone who has ever looked at most of the books on English grammar, it is clear that these sorts of books are sometimes not informed by a linguistic analysis of a language's grammar (and, in the case of English at least, many of these sorts of books include things that are completely at odds with current linguistic description and instead based on arbitrary preferences of the author). While I doubt that such a separation is true for Ancient Greek, my point is that linguists are more likely to be familiar with grammatical materials that are not designed for language teaching/learning (except through their personal interest in such a thing, but this site is about professional rather than personal insights).
If the question were something more like "Is there a comprehensive grammatical description of Language A that covers features such as X, Y and Z that I can use for a typological comparison with Language B?", I would consider the question on-topic, because it clearly seeks a linguistically-informed description for the purposes of linguistic research (and some old grammars of languages can certainly be difficult to track down or find any records of).
There are lots of other places you can ask for a recommendation for materials to help you learn Ancient Greek, and which fit your criteria (places where people may be able to help you better anyway, if the shared interest is more about materials that are useful for teaching/learning rather than linguistic analysis). You could try contacting the people at this blog about (Ancient) Greek language and linguistics, which also has a page about Greek grammars. Ancient Greek is still a reasonably widely-studied language, so a Google search also gives you a lot of different forums and reference pages, and Amazon etc. overviews can often give you a good idea of the contents of any books.
