Have you seen Amethyst hitting your relay limits?
Discussion
I think the different settings of each relay will indeed bring difficulties to the client. Similarly, relay operators also spend a lot of time to investigate and adjust in order to support different clients. I saw the problem of exceeding the limit before, but I just changed the settings, I haven‘t seen what the client is.
I’m testing some clients on iOS now. I haven‘t had time to see Amethests yet. Is the subscription ID a 4 character string? I noticed that the requests for this kind of subscription number are quite frequent.