Are Systematic Reviews Efficient To Familiarize Yourself With The State-of-the-Art? Problem
I have to familiarize myself with a new sub-field fast, to the point where I can recommend an agenda/recommendation for further research. I thought about doing a systematic literature review to achieve this, but have to work somewhat cost-efficient due to external deadlines that I have no influence on.
Background
Systematic Literature Review
When I say &quot;systematic literature review&quot; (SLR) I'm referring to a speficic concept which originated in medical science and was  introduced to computer science by Kitchenham (2004), for a hands-on guide see Kuhrmann et al. (2017).
Purpose
The purpose of conducting a systematic review would be to acquire the necessary knowledge to be able to argument for new research endeavors (i.e. defend their relevance). Additionally, it would be nice to get a publication out of this, which is part of the reason why I think about doing a systematic review instead of just writing up a state-of-the-art document for myself.
Narrowness
The topic I want to research is part of Software Engineering, and deals with the application of a specific concept in a more-or-less specific environment. I could not find any systematic reviews (or indeed, any reviews) covering this.
What I found
Ressources
Time
The approximate time to become familiar with the state-of-the-art in a field that one is already familiar with, according to this answer, is one year. Even though the question was about a PhD, and not just a work project, this strikes me as a little high. An answer to a question about the usefulness of SLRs warns that spending 6 months on a SLR for just a paper is excessive.
Human effort
Even though the literature on SLR recommends multiple researchers, this answer says that it is quite possible to conduct and report a SLR on your own. I might get a senior colleague to look over my draft and maybe recommend specific papers, but I should expect to do almost all of the work on my own.
Paywalls
I don't have institutional access to a lot of journals and such, which means that I will mostly be able to read exactly those papers that are either published in Open Access journals or are otherwise available through researchgate and similar platforms. This answer predicts that a restriction like that will render the SLR of little interest to publishers. Since I not only support Open Access publications for various reasons, but also really don't have a lot of choice in the matter (I can't convince my institution to pay for the access I want, nor do I have the money to pay for all those subscriptions), I do hope that this is not true.
Usefulness
Even though it is considered useful to write a SLR in order to get a good foundation in a field, it might be more efficient to just read some papers (specifically reviews, if they exist) and follow the references. However, this efficiency calculation does not factor in the expected utility of publishing a SLR as paper.
Questions
Main question
Is it really useful to write SLRs in order to familiarize yourself with a topic in a short time, while a publication is nice-to-have but not mandatory?
Sub-questions

Is it possible to do a SLR on your own, in a matter of weeks?
Do paywalls effectively keep me from writing and/or publishing SLRs?
Performing a systematic review is very time consuming. Also, it may result in a &quot;high dispersive work&quot;, if a very specific research question is not set &quot;a priori&quot;.
Also, SR is not only &quot;indexing&quot; evidence, but also effectively aggregating them in a readable and useful summary. If you are not an expert in that field, you may not be able to do that, and the quality of the overall work may be low.
If your goal is to improve your knowledge in a specific field, performing a systematic review may not be the most suitable option in the first place. You'd rather read existing reviews and summary (if any) - this would be extremely more time-effective.
To answer to the other two questions:

Yes, it is possible to do in a matter of weeks, but not entirely on your own (the process of screening requires at least two independent reviewers, according to the PRISMA guidelines).
Yes, if you are not able to reach those literature that meets the inclusion criteria of your SR (and this is quite probable).