I did it once in one of my projects. It's basically hand-picking weights from Pytorch model's layers to TensorFlow model's layers, but it feels more reliable than relying on ONNX with a bunch of warnings.

Though there are not much tutorials or blog posts about this, I will try creating a github repo for this later (just examples with simple layers), so many more people will know that this technique exists.

Agreed with all the folks, if your model is far beyond ordinary CNN and RNN then ONNX will give you a bunch of warnings that confuses you.