I had a client who was using sentence transformers with elasticsearch already. My colleague suggested switching to haystack to enable a larger number of model architectures. Switching over to haystack was pretty straightforward because we just used it as a wrapper around sentence transformers, but I do remember some inconvenience around all the other dependencies that haystack pulled in.

Haystack does a lot more besides just wrapping sentence transformers, and we weren't using the rest of it, so it was just a lot of extra dependencies sitting around taking up disk space and memory (I think we had to go up to a larger instance size). I remember feeling a bit frustrated that the dependencies weren't split up into "core" and "optional" in a more fine-grained way, but maybe most users don't mind and so it doesn't make sense for them to prioritize that?

[edit: looks like there's an open issue related to this: https://github.com/deepset-ai/haystack/issues/1070]

[edit 2: 'JPKab happy to share more about using huggingface and elasticsearch. email is in my profile]