Unity component that keeps the editor scene view active when entering play mode.

KeepSceneViewActive.cs

using UnityEngine;

/// <summary>
/// Keeps the editor scene view active when entering play mode.
/// Place this component on any game object.
/// </summary>
public class KeepSceneViewActive : MonoBehaviour
{
    [Tooltip("Keep the editor scene view active")]
    public bool KeepActive = true;

#if UNITY_EDITOR
    void Start()
    {
        if (this.KeepActive && Application.isEditor)
        {
            UnityEditor.EditorWindow.FocusWindowIfItsOpen(typeof(UnityEditor.SceneView));
        }
    }
#endif
}