export efficientnetv2 to onnx?

[LukeAI]

Based on the example given in geffnet (which works for efficientnet), I try to export a timm model to ONNX (tf_efficientnetv2_b2) as follows:

    model = timm.create_model(model,
                              pretrained=False,
                              checkpoint_path=checkpoint_path,
                              exportable=True,
                              num_classes=8)
    model.eval()
    model.to(DEVICE)
    # B x C x H x W
    example_input = torch.randn(EXPORT_BATCH_SIZE, 3,
                                32*config['train_width'], 32*config['train_width']).to(DEVICE)

    # Run model once before export trace
    model(example_input)
    
    # https://pytorch.org/tutorials/advanced/super_resolution_with_onnxruntime.html
    input_names = ["input0"]
    output_names = ["output0"]
    if dynamic_size:
        dynamic_axes = {'input0': {0: 'batch'}, 'output0': {0: 'batch'}}
        dynamic_axes['input0'][2] = 'height'
        dynamic_axes['input0'][3] = 'width'
    else:
        dynamic_axes = {}
    if aten_fallback:
        export_type = torch.onnx.OperatorExportTypes.ONNX_ATEN_FALLBACK
    else:
        export_type = torch.onnx.OperatorExportTypes.ONNX
    torch.onnx.export(model, example_input, onnx_name,
                      do_constant_folding=True, input_names=input_names,
                      output_names=output_names, dynamic_axes=dynamic_axes)

but I get the following error:

~/.pyenv/versions/3.8.8/envs/classifier/lib/python3.8/site-packages/torch/onnx/symbolic_helper.py in _onnx_opset_unsupported_detailed(op_name, current_opset, supported_opset, reason)
    231 
    232 def _onnx_opset_unsupported_detailed(op_name, current_opset, supported_opset, reason):
--> 233     raise RuntimeError('Unsupported: ONNX export of {} in '
    234                        'opset {}. {}. Please try opset version {}.'.format(op_name, current_opset, reason, supported_opset))
    235 

RuntimeError: Unsupported: ONNX export of Pad in opset 9. The sizes of the padding must be constant. Please try opset version 11.

I understand that exporting timm to onnx isn't documented or supported but... I guess my questions are:

1. Is it likely that a soon-to-be-released efficientnetv2 will not run into this problem of non-constant padding? and therefore be more likely to be exportable?

2. If not, how difficult would it be to edit Timm to support this export functionality? at least for this model.