MacOS: conditional CommandGroup - swift

Question

I have a custom CommandGroup (customPasteboardCommands - it replaces the built-in .pasteboard group) which I would like to render conditionally.
What is the correct syntax?
I tried two ways, none of them worked:
First
if viewModel.shouldUseCustomCommandGroup {
customPasteboardCommands
}
Error:
Closure containing control flow statement cannot be used with result
builder 'CommandsBuilder'
Second:
viewModel.shouldUseCustomCommandGroup ? customPasteboardCommands : EmptyCommands()
Error:
Result values in '? :' expression have mismatching types 'some
Commands' and 'EmptyCommands'
Full code:
App.swift
import SwiftUI
#main
struct macos_playgroundApp: App {
private let viewModel = ViewModel()
var body: some Scene {
WindowGroup {
Button("Toggle custom CommandGroup") {
viewModel.onToggleCustomCommandGroup()
}
}
.commands {
commands
}
}
#CommandsBuilder
var commands: some Commands {
emptyNewItemCommands
viewModel.shouldUseCustomCommandGroup ? customPasteboardCommands : EmptyCommands()
}
var emptyNewItemCommands: some Commands {
CommandGroup(replacing: .newItem) {}
}
var customPasteboardCommands: some Commands {
CommandGroup(replacing: .pasteboard) {
Button("Select All") {
print("Custom select all activated")
}
.keyboardShortcut("a", modifiers: [.command])
}
}
}
ViewModel.swift
import Foundation
class ViewModel: ObservableObject {
#Published var shouldUseCustomCommandGroup: Bool = false
func onToggleCustomCommandGroup() {
shouldUseCustomCommandGroup = !shouldUseCustomCommandGroup
}
}