Unfortunately it's probably not in the cards in the near term just do to other priorities and insufficient demand (plus alternatives like HIP for AMD). I will say a lot of us here at OmniSci would kill to leverage the latent GPUs in our Macs and other places, so we'd welcome any community help towards this end (it's not a trivial thing to add, but also not particularly difficult either, just work).
We'll plan to update that issue with the above.