Backspace broken in Vi multi-line insertion mode

[davidbrochart]

It looks like in Vi multi-line insertion mode, backspace has no effect (I can see that in pyvim for instance).
Also, tab doesn't work.

[JaDogg]

I've done it this way (Work around) for inserting tab characters.

class MarkdownArea(TextArea):
    def __init__(self, readonly=False):
        super().__init__(
            lexer=PygmentsLexer(MarkdownLexer),
            scrollbar=True,
            line_numbers=True,
            focus_on_click=not readonly,
            input_processors=[TabsProcessor(), DisplayMultipleCursors()],
            wrap_lines=True,
            read_only=readonly,
            focusable=not readonly,
        )
    
    def indent(self):
        if self.read_only:
            return
        current_doc = self.document
        self.document = current_doc.paste_clipboard_data(ClipboardData(text="\t"))

Then I created a key binding that calls this method