What is transform.Rotate doing internally when going beyond 360° or 0°?

Title says it all. The reason why I'm asking this is because I have Vector3 points which should follow the corner points of a cube. It's kinda working but there appear to be "2 sections of 360°". At the start everything works fine but if the rotation goes beyond 360° or below 0° the vectors rotate in the opposite direction of the cube until the rotation goes beyond 360° degrees again. using UnityEngine;

 public class Move : MonoBehaviour {
 
     float movespeed;
     float rotspeed;
 
     Vector3 pointA = new Vector3();
     Vector3 pointB = new Vector3();
     Vector3 pointC = new Vector3();
     Vector3 pointD = new Vector3();
     Vector3 pointE = new Vector3();
     Vector3 pointF = new Vector3();
     Vector3 pointG = new Vector3();
     Vector3 pointH = new Vector3();
 
     void Awake() {
         
         // force 60 fps
         Application.targetFrameRate = 60;
     }
 
     // Use this for initialization
     void Start () {
 
     }
     
     // Update is called once per frame
     void Update () {
 
         movespeed = Input.GetAxisRaw("Vertical") * Time.deltaTime;
         if (movespeed > 0) movespeed *= 4;
         transform.Translate(0, 0, movespeed);
 
         rotspeed = Input.GetAxisRaw("Horizontal") * Time.deltaTime * 60;
         transform.Rotate(0, rotspeed, 0);
 
         // initialize corner points of bounding box
         pointA.Set(-0.5f, 0, -0.5f);
         pointB.Set(0.5f, 0, -0.5f);
         pointC.Set(0.5f, 0, 0.5f);
         pointD.Set(-0.5f, 0, 0.5f);
         pointE.Set(-0.5f, 1f, -0.5f);
         pointF.Set(0.5f, 1f, -0.5f);
         pointG.Set(0.5f, 1f, 0.5f);
         pointH.Set(-0.5f, 1f, 0.5f);
 
         // rotate around y-Axis with transform's y-rotation
         pointA = Quaternion.AngleAxis(transform.eulerAngles.y, new Vector3(transform.rotation.x, transform.rotation.y, transform.rotation.z)) * pointA;
         pointB = Quaternion.AngleAxis(transform.eulerAngles.y, new Vector3(transform.rotation.x, transform.rotation.y, transform.rotation.z)) * pointB;
         pointC = Quaternion.AngleAxis(transform.eulerAngles.y, new Vector3(transform.rotation.x, transform.rotation.y, transform.rotation.z)) * pointC;
         pointD = Quaternion.AngleAxis(transform.eulerAngles.y, new Vector3(transform.rotation.x, transform.rotation.y, transform.rotation.z)) * pointD;
         pointE = Quaternion.AngleAxis(transform.eulerAngles.y, new Vector3(transform.rotation.x, transform.rotation.y, transform.rotation.z)) * pointE;
         pointF = Quaternion.AngleAxis(transform.eulerAngles.y, new Vector3(transform.rotation.x, transform.rotation.y, transform.rotation.z)) * pointF;
         pointG = Quaternion.AngleAxis(transform.eulerAngles.y, new Vector3(transform.rotation.x, transform.rotation.y, transform.rotation.z)) * pointG;
         pointH = Quaternion.AngleAxis(transform.eulerAngles.y, new Vector3(transform.rotation.x, transform.rotation.y, transform.rotation.z)) * pointH;
 
         // translate points to transform's position
         pointA.x += transform.position.x;
         pointB.x += transform.position.x;
         pointC.x += transform.position.x;
         pointD.x += transform.position.x;
         pointE.x += transform.position.x;
         pointF.x += transform.position.x;
         pointG.x += transform.position.x;
         pointH.x += transform.position.x;
 
         pointA.y += transform.position.y - 0.5f;
         pointB.y += transform.position.y - 0.5f;
         pointC.y += transform.position.y - 0.5f;
         pointD.y += transform.position.y - 0.5f;
         pointE.y += transform.position.y - 0.5f;
         pointF.y += transform.position.y - 0.5f;
         pointG.y += transform.position.y - 0.5f;
         pointH.y += transform.position.y - 0.5f;
 
         pointA.z += transform.position.z;
         pointB.z += transform.position.z;
         pointC.z += transform.position.z;
         pointD.z += transform.position.z;
         pointE.z += transform.position.z;
         pointF.z += transform.position.z;
         pointG.z += transform.position.z;
         pointH.z += transform.position.z;
 
         // draw bounding box
         Debug.DrawLine(pointA, pointB, Color.red, 0, false);
         Debug.DrawLine(pointA, pointD, Color.red, 0, false);
         Debug.DrawLine(pointB, pointC, Color.red, 0, false);
         Debug.DrawLine(pointC, pointD, Color.red, 0, false);
         Debug.DrawLine(pointA, pointE, Color.red, 0, false);
         Debug.DrawLine(pointB, pointF, Color.red, 0, false);
         Debug.DrawLine(pointC, pointG, Color.red, 0, false);
         Debug.DrawLine(pointD, pointH, Color.red, 0, false);
         Debug.DrawLine(pointE, pointF, Color.red, 0, false);
         Debug.DrawLine(pointE, pointH, Color.red, 0, false);
         Debug.DrawLine(pointF, pointG, Color.red, 0, false);
         Debug.DrawLine(pointG, pointH, Color.red, 0, false);
 
         Debug.Log(transform.eulerAngles.y);
     }
 }

I know how to fix this by checking in which "360° section" I am and writing it like this for the other "section":

 pointA = Quaternion.AngleAxis(360f - transform.eulerAngles.y, new Vector3(transform.rotation.x, transform.rotation.y, transform.rotation.z)) * pointA;

Thanks in advance!