Why does torch not support onnx export with opset>17? dynamo_export not working properly?

So it would really be nice if the latest opset version of onnx would work because they are necessary to go from experimental level to production. Not having the option of opset >17 somehow negates the possibility to use torch for training models, since the new nvidia inference server with tensor rt rely on it.

I also tried dynamo_export for opset=18 but when tryining to use dynamic_shapes it does not work, which makes the model not batchable. It just makes dynamic shapes for the last two dimensions but not for batching.

My code for the dynamo_export is:

input = torch.randn([1, 3, 112, 112])
opts = torch.onnx.ExportOptions()
opts.dynamic_shapes = True
ox_p = torch.onnx.dynamo_export(model, input, export_options=opts)

Maybe you have an idea how to make the first dimension dynamic in dynamo_export?

Bets regards