Lack of DropDownButton menu shadow theming in Flutter

main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'DropDownButton shadow test',
      theme: ThemeData.light().copyWith(
        colorScheme: const ColorScheme.light(
          // TODO does nothing
          shadow: Colors.red,
        ),
        dialogTheme: const DialogTheme(
          // TODO does nothing
          shadowColor: Colors.red,
        ),
        drawerTheme: const DrawerThemeData(
          // TODO does nothing
          shadowColor: Colors.red,
        ),
        dropdownMenuTheme: const DropdownMenuThemeData(
          menuStyle: MenuStyle(
            // TODO only works for DropDownMenu
            shadowColor: MaterialStatePropertyAll(Colors.red),
          ),
        ),
        menuBarTheme: const MenuBarThemeData(
          style: MenuStyle(
            // TODO does nothing
            shadowColor: MaterialStatePropertyAll(Colors.red),
          ),
        ),
        menuButtonTheme: const MenuButtonThemeData(
          style: ButtonStyle(
            // TODO does nothing
            shadowColor: MaterialStatePropertyAll(Colors.red),
          ),
        ),
        menuTheme: const MenuBarThemeData(
          style: MenuStyle(
            // TODO does nothing
            shadowColor: MaterialStatePropertyAll(Colors.red),
          ),
        ),
        navigationBarTheme: const NavigationBarThemeData(
          // TODO does nothing
          shadowColor: Colors.red,
        ),
        navigationDrawerTheme: const NavigationDrawerThemeData(
          // TODO does nothing
          shadowColor: Colors.red,
        ),
        popupMenuTheme: const PopupMenuThemeData(
          // TODO does nothing
          shadowColor: Colors.red,
        ),
      ),
      home: Scaffold(
        appBar: AppBar(),
        body: Center(
          child: DropdownButton(
            onChanged: (_) {},
            value: 1,
            items: const [
              DropdownMenuItem(
                value: 1,
                child: Text("Item 1"),
              ),
              DropdownMenuItem(
                value: 2,
                child: Text("Item 2"),
              ),
            ],
          ),
        ),
      ),
    );
  }
}