I haven’t looked yet but I might be a candidate for something like this, maybe. I’m RAM constrained and, to a lesser extent, CPU constrained. It would be nice to offload some of that. That said, I don’t think I would buy a cluster of Macs for that. I’d probably buy a machine that can take a GPU.
I’m not particularly interested in training models, but it would be nice to have eGPUs again. When Apple Silicon came out, support for them dried up. I sold my old BlackMagic eGPU.
That said, the need for them also faded. The new chips have performance every bit as good as the eGPU-enhanced Intel chips.
eGPU with an Apple accelerator with a bunch or RAM and GPU cores could be really interesting honestly. I’m pretty sure they are capable of designing something very competitive especially in terms of performance per watt.