issue on Mac M3: BFloat16 is not supported on MPS

[dfl]

ERROR:root:!!! Exception during processing !!!
ERROR:root:Traceback (most recent call last):
  File "/Users/dfl/sd/ComfyUI/execution.py", line 152, in recursive_execute
    output_data, output_ui = get_output_data(obj, input_data_all)
                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/dfl/sd/ComfyUI/execution.py", line 82, in get_output_data
    return_values = map_node_over_list(obj, input_data_all, obj.FUNCTION, allow_interrupt=True)
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/dfl/sd/ComfyUI/execution.py", line 75, in map_node_over_list
    results.append(getattr(obj, func)(**slice_dict(input_data_all, i)))
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/dfl/sd/ComfyUI/custom_nodes/ComfyUI-DiffusersStableCascade/nodes.py", line 44, in process
    self.prior = StableCascadePriorPipeline.from_pretrained("stabilityai/stable-cascade-prior", torch_dtype=torch.bfloat16).to(device)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/dfl/sd/ComfyUI/venv/src/diffusers/src/diffusers/pipelines/pipeline_utils.py", line 862, in to
    module.to(device, dtype)
  File "/Users/dfl/sd/ComfyUI/venv/lib/python3.11/site-packages/transformers/modeling_utils.py", line 2595, in to
    return super().to(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/dfl/sd/ComfyUI/venv/lib/python3.11/site-packages/torch/nn/modules/module.py", line 1160, in to
    return self._apply(convert)
           ^^^^^^^^^^^^^^^^^^^^
  File "/Users/dfl/sd/ComfyUI/venv/lib/python3.11/site-packages/torch/nn/modules/module.py", line 810, in _apply
    module._apply(fn)
  File "/Users/dfl/sd/ComfyUI/venv/lib/python3.11/site-packages/torch/nn/modules/module.py", line 810, in _apply
    module._apply(fn)
  File "/Users/dfl/sd/ComfyUI/venv/lib/python3.11/site-packages/torch/nn/modules/module.py", line 810, in _apply
    module._apply(fn)
  File "/Users/dfl/sd/ComfyUI/venv/lib/python3.11/site-packages/torch/nn/modules/module.py", line 833, in _apply
    param_applied = fn(param)
                    ^^^^^^^^^
  File "/Users/dfl/sd/ComfyUI/venv/lib/python3.11/site-packages/torch/nn/modules/module.py", line 1158, in convert
    return t.to(device, dtype if t.is_floating_point() or t.is_complex() else None, non_blocking)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: BFloat16 is not supported on MPS

I start comfy with this script:

PYTORCH_ENABLE_MPS_FALLBACK=1
./venv/bin/python main.py --force-fp16

tried changing various permutations to no effect

[azrahello]

same on m2 ultra

[fantomac]

Same here : https://github.com/kijai/ComfyUI-DiffusersStableCascade/issues/6#issuecomment-1947101857