@Zugzug, my experience is that it depends completely on the health system where you are. If you go to a private otologist I think it should be relatively easy to get them prescribed, especially in the early stages. I would choose a surgeon ideally, you need someone with a good hand, but the procedure and the material injected are very standard. However, if you stay with public health services, it may be trickier. Let me tell you my experience in that regard.
For the UK, I have a good doctor with the NHS, this doctor is supportive, and also a good person, and a tinnitus expert, research level, but this specialist refuses to do anything unless there is very strong evidence for the therapy. So we did the usual tests, hearing tests, OAE, MRI, all the tests for balance, but no cochleography for example. I was denied injections there because the relative stability of my hearing (up to 8khz) would be against autoimmune disease, and they discarded the hydrops hypothesis that was suggested partly by the electrocochleography (ECOG) I did privately because there was no other evidence of hydrops. Eventually we came to a standstill, I was begging them to try something else because I was desperate, I had long discussions but this NHS specialist would try to convince me that all the things I wanted to try were not supported by evidence, and would try nothing except referring me for psychological support. I was left with an "anxiety makes tinnitus worse" diagnosis that I didn't believe for a second, as I could relax very effectively but the tinnitus would never even fluctuate. I tried tinnitus-oriented osteopathy, acupuncture, meditation. I could relax but the tinnitus would not move one inch, and kept worsening. So I went private, and one of the first thing they told me were injections. This first private specialist who had done the ECOG and wanted to do injections wanted also to insert grommets in my ears. I was not convinced of that as I thought my Eustachian tubes were fine and went to a second private specialist who checked them thoroughly and told me I definitely didn't need grommets. This was also the opinion of the NHS doctor. This made me suspicious of the first private specialist. The tendency if you go private in the UK is to do more than needed because they make money that way, hence grommets when you don't need them. This made me suspicious of the first specialist regarding also injections, but in retrospective perhaps I could have tried the injections anyway. At the time I asked the NHS doctor whether he would recommend them but he said no, he discouraged me to do them even privately, while the second private specialist told me he thought there was only a remote possibility they would help. So I waited and did psychotherapy, but it didn't really help me much. Eventually, out of desperation, I recently went to see a third private specialist, and he also suggested injections based on the limited evidence (but no grommets fortunately).
I am not sure injections are fully supported by the evidence in my case, but the point is that I have to try something, as long as it is reasonable and the risk/benefit analysis makes sense. I think this specialist sensed my sense of urgency and proposed a kind of standard procedure. I would have liked him to dare more, but I guess there is not much else one can do at this stage.
So it's a little mess in the UK, you really need to go private to see some action beyond psychotherapy and very obvious diagnoses where the treatment is granted, or at least this is my experience, perhaps other people have been luckier.
I don't remember where you are based, I guess in the US and EU it should be relatively easy to access this treatment with a little research and going private, I am not sure about public health though. The NHS said very clearly "no" to me, and maybe they are right, who knows, but I need to try solutions as I am desperate.
I take the opportunity to ask again to other forum members if they have experience with steroid injections late in the process (20 months+). I had posted this as a new topic in the support forum but this has been appended here, so I am concerned not many people will see this.