TL;DR: if you don't know enough about the software, or you don't have time/interest to write a good answer that evaluates all requirements set in the question, instead of answering you should leave a comment. Probably something like this.
I think this is might be a good fit. I don't know enough to write a full answer. If you have more experience with this, feel free to add an answer.
You won't get reputation for this, but you can still offer a suggestion, without leaving incomplete answer and thus degrade the overall quality of the site.
Now to the longer answer. First, this is a really low-hanging fruit. In addition to so-called primary requirement, the question lists three points (bolded parts). Clearly all of these are mandatory.
- makes it relatively simple to setup and initialize…
- …one or more local repos.: after edit, this is kind-of answered.
- …a single git+ssh remote.: this is supported; why it's not even mentioned on the answer? Is it easy to setup? Does it work well (if you have used TortoiseGit, you probably have some experiences. That could be just "I never encountered any problems with git+ssh")
- …authentication using an RSA key pair (generation of this would be a bonus).: of course this is supported. Why it's not mentioned? Is it easy to setup? It seems it doesn't support generating public keys, so maybe it's good idea to point to any software that can generate keys on windows, for instance, puttygen.
The only requirement that's defined as "preferably" is whether the software is open source or not. Even that is not addressed in your answer, even though the answer is available immediately on the linked page. As it is immediately visible on the project website, why it should be mentioned in the answer? Well, because the answer should answer the question, not just provide links to resources. (This is now edited to the answer.)
Finding answers to these requirements does not take more than a few minutes (which applies to everyone else too, but the idea of SE sites is to provide high-quality summaries, not collections of links). However, you really should add value by writing your own experiences with these. This brings us to the second point.
I like to quote this "Ground rules" post:
Good answers on this site will be in the form of honest testimonials that share first hand experience with something and why it meets the needs of the asker.
Evaluating options you gave:
Research how the tool meets all the requirements mentioned in question [...] Bottom line - Good answer (although not perfect) won't be posted.
Yes. That's exactly what you should do. In my opinion, it is okay to skip some less-important features (as defined by the question), as long as that is mentioned. This site degrades to software lists, if people looking at the answers are expected to install every recommended software and check whether it fits the requirements.
Refrain from posting, since I am not sure how my answer fits all the requirements, even less important ones. Bottom line - Good answer (although not perfect) won't be posted.:
See number 1.
Post my answer, explain how the tool meets the most important requirement. [...] Bottom line - Good answer (although not perfect) is Down-voted.:
As the answer does not provide value - except what you can already get from hitting Google and evaluating answers by yourself, in my opinion, down-voting is the right approach. Unless people reading it have first-hand experiences and can improve the answer.
From meta post linked by Flyk on comments: "How should we treat answers that doesn't fit all requirements?":
Acceptable answers on this site will address a bullet list of requirements and constraints defined in the question.
The point is, good answer does not have to fit all requirements, but it must still evaluate how well it fits the requirements. With this question, doing that is really easy.