Hello @Louis-Cheng-Liu!
I could figure out with this problem. The problem was that I added method forward_export() to git-cloned ultralytics repo, and this doesn’t affect pt->onnx conversion process. Instead this I must add forward_export() to pip-installed ultralytics package, and after that everything works (but my VIM4 still reboots wnile detection as i described in Yolov7_tiny demo - #9 by Louis-Cheng-Liu).
I think it will be good if you add this tip in your instruction for people who aren’t python developers (like me =)).