Been running lemonade for some time on my Strix Halo box. It dispatches out to other backends that they include, like diffusion and llama. I actually don't like their combined server, and what I use instead is their llama CPP build for ROCm.
https://github.com/lemonade-sdk/llamacpp-rocm
But I'm not doing anything with images or audio. I get about 50 tokens a second with GPT OSS 120B. As others have pointed out, the NPU is used for low-powered, small models that are "always on", so it's not a huge win for the standard chatbot use case.
Even small NPUs can offload some compute from prefill which can be quite expensive with longer contexts. It's less clear whether they can help directly during decode; that depends on whether they can access memory with good throughput and do dequant+compute internally, like GPUs can. Apple Neural Engine only does INT8 or FP16 MADD ops, so that mostly doesn't help.