【Unity(C#)】UniRxを使ってスキップ機能付きのテキストを1文字ずつ表示させる実装を試したけど微妙だった

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

public class TextPerOneWrite : MonoBehaviour
{
    [SerializeField]
    float m_textInterval = 0.2f;

    [SerializeField]
    KeyCode m_keyCode = KeyCode.Space;

    Text m_windowText;

    IDisposable m_textDispose;
    IDisposable m_updateDispose;

    void Start()
    {
        m_windowText = this.gameObject.GetComponent<Text>();
        m_windowText.text = "";

        //実行サンプル 文字を1文字ずつ出す
        ShowPerOne("ウホウホバナナヨコセ");
        ShowPerOne("ウホウホバナナヨコセ(早口)", 0.1f);

    }

    void ShowPerOne(string commentText)
    {
        m_windowText.text = "";

        if (m_textDispose != null)
        {
            m_textDispose.Dispose();
            m_updateDispose.Dispose();
        }

        m_textDispose = Observable.Interval(TimeSpan.FromSeconds(m_textInterval))
            .Take(commentText.Length)
            .Select(_ => 1)
            .Scan((accumulation, newValue) => accumulation + newValue)
            .DoOnCompleted(() => m_updateDispose.Dispose())
            .SubscribeToText(m_windowText, length => commentText.Substring(0, length))
            .AddTo(this);

        //特定のキー入力で文字を1文字ずつ出す機能を止める
        m_updateDispose =  this.UpdateAsObservable()
            .FirstOrDefault(_ => Input.GetKeyDown(m_keyCode))
            .Subscribe(_ =>
            {
                m_textDispose.Dispose();
                m_windowText.text = commentText;
            });
    }

    void ShowPerOne(string commentText, double textInterval)
    {
        m_windowText.text = "";

        if (m_textDispose != null)
        {
            m_textDispose.Dispose();
            m_updateDispose.Dispose();
        }

        m_textDispose = Observable.Interval(TimeSpan.FromSeconds(textInterval))
            .Take(commentText.Length)
            .Select(_ => 1)
            .Scan((accumulation, newValue) => accumulation + newValue)
            .DoOnCompleted(()=>m_updateDispose.Dispose())
            .SubscribeToText(m_windowText, length => commentText.Substring(0, length))
            .AddTo(this);

        //特定のキー入力で文字を1文字ずつ出す機能を止める
        m_updateDispose =  this.UpdateAsObservable()
           .FirstOrDefault(_ => Input.GetKeyDown(m_keyCode))
           .Subscribe(_ =>
           {
               m_textDispose.Dispose();
               m_windowText.text = commentText;
           });
    }
}

.Scan((accumulation, newValue) => accumulation + newValue)

    if (m_textDispose != null)
    {
        m_textDispose.Dispose();
        m_updateDispose.Dispose();
    }