【Unity】【UniRx】AsyncReactiveCommand で処理中は複数のボタンを押せなくする

using System;
using UnityEngine;
using UnityEngine.UI;
using UniRx;

public class Sample : MonoBehaviour
{
    // ボタン 1
    [SerializeField]
    private Button _button1;
    // ボタン 2
    [SerializeField]
    private Button _button2;
    // ボタンの押下許可
    private BoolReactiveProperty _sharedCanExecuteSource = new BoolReactiveProperty(true);
    
    private void Start()
    {
        var command1 = new AsyncReactiveCommand(this._sharedCanExecuteSource);
        command1.BindToOnClick(this._button1, _ =>
        {
            return Observable.Timer(TimeSpan.FromSeconds(1))
                .ForEachAsync(__ => Debug.Log($"button1"));
        });
        
        var command2 = new AsyncReactiveCommand(this._sharedCanExecuteSource);
        command2.BindToOnClick(this._button2, _ =>
        {
            return Observable.Timer(TimeSpan.FromSeconds(1))
                .ForEachAsync(__ => Debug.Log($"button2"));
        });
    }
}

省略して下記のように書くこともできる。

using System;
using UnityEngine;
using UnityEngine.UI;
using UniRx;

public class Sample : MonoBehaviour
{
    // ボタン 1
    [SerializeField]
    private Button _button1;
    // ボタン 2
    [SerializeField]
    private Button _button2;
    // ボタンの押下許可
    private BoolReactiveProperty _sharedCanExecuteSource = new BoolReactiveProperty(true);
    
    private void Start()
    {
        this._button1
            .BindToOnClick(this._sharedCanExecuteSource, _ => 
            {
                return Observable.Timer(TimeSpan.FromSeconds(1))
                    .ForEachAsync(__ => Debug.Log($"button1"));
            });
        this._button2
            .BindToOnClick(this._sharedCanExecuteSource, _ => 
            {
                return Observable.Timer(TimeSpan.FromSeconds(2))
                    .ForEachAsync(__ => Debug.Log($"button2"));
            });
    }
}