In essence, what I want is for Vim in Joplin to treat wrapped text lines as real lines instead of operating on line breaks. But only when moving the cursor (so not deleting a line etc.).
The current behavior is that when you press up or down while in command mode in vim, the cursor moves up one line up or one line down. The problem is that vim works on lines based on line breaks. So if there is a line that is longer than the width of the editor, it will wrap over visibly to the next line, but vim will still think that it's a single line and treat is accordingly.
Now, if there is a long paragraph and I would like to move up one line to make a quick edit, it will jump to the beginning of the paragraph. Instead, it should move up based on what appears to be another line (because of text wrapping).