We released Spine 4.2.45-beta today and now you can copy and paste weights! 🎉
There are many things that can be copied with the same Ctrl+C
hotkey, so you need to be careful about the current selection and which view is active. The operation might be changed in a future version, but as it stands now, you might copy the bone transforms when you try to copy the weights as shown below:
<Deleted>
Check the toast messages that appear at the bottom of the viewport to verify that the copy is complete.