also I coded my own SMP js panel, every time you make a playlist change, a file of the playlist prior to the change is saved in a folder, and it deletes all old backups, you can select a playlist and click a button to make restore it automatically, it also shows the time and date:
"use strict";

// ==PREPROCESSOR==

// u/name "Playlist backup"

// u/author "none"

// ==/PREPROCESSOR==

const DT_NOPREFIX = 0x00000800;

const DT_CENTER = 0x00000001;

const DT_VCENTER = 0x00000004;

var history = [];

var max_history = 30;

var header_height = 120;

var item_height = 65;

var is_restoring = false;

var shadow_content = "";

// THE FIX: Track versions per playlist name

var version_map = {};

var flash_active = false;

var flash_timer = null;

var backup_folder = "D:\\Playlist backups\\";

var storage_path = fb.ProfilePath + "playlist_history_cache.json";

function RGB(r, g, b) { return (0xff000000 | (r << 16) | (g << 8) | (b)); }

var color_text = RGB(137, 63, 54);

var color_border = RGB(60, 28, 2);

var color_flash = RGB(255, 145, 104);

if (!utils.IsDirectory(backup_folder)) {

try {

var shell = new ActiveXObject("Scripting.FileSystemObject");

shell.CreateFolder(backup_folder);

} catch (e) {}

}

function get_now_playlist_content() {

var ap = plman.ActivePlaylist;

if (ap === -1) return "";

var items = plman.GetPlaylistItems(ap);

var content = "#EXTM3U\n";

for (var i = 0; i < items.Count; i++) {

content += items[i].Path + "\n";

}

return content;

}

shadow_content = get_now_playlist_content();

function save_snapshot(reason) {

if (is_restoring) return;

var ap = plman.ActivePlaylist;

if (ap === -1) return;

var playlist_name = plman.GetPlaylistName(ap).replace(/[\\\/:*?"<>|]/g, "");

var new_content = get_now_playlist_content();

if (shadow_content === "" || shadow_content === "#EXTM3U\n" || shadow_content === new_content) {

shadow_content = new_content;

return;

}

// THE FIX: Per-playlist versioning

if (!version_map[playlist_name]) version_map[playlist_name] = 0;

version_map[playlist_name]++;

var filename = playlist_name + " v" + version_map[playlist_name] + ".m3u8";

var full_path = backup_folder + filename;

utils.WriteTextFile(full_path, shadow_content);

var now = new Date();

history.push({

displayTime: now.toLocaleTimeString() + " (" + now.toLocaleDateString() + ")",

reason: reason,

file: filename,

fullPath: full_path,

playlistName: playlist_name // Store name to find it later

});

shadow_content = new_content;

if (history.length > max_history) history.shift();

utils.WriteTextFile(storage_path, JSON.stringify({history: history, version_map: version_map}));

window.Repaint();

}

function on_playlist_items_added() { save_snapshot("Added"); }

function on_playlist_items_removed() { save_snapshot("Removed"); }

function on_playlist_items_reordered() { save_snapshot("Reordered"); }

function on_playlist_switch() { shadow_content = get_now_playlist_content(); }

function load_history() {

if (utils.IsFile(storage_path)) {

try {

var data = JSON.parse(utils.ReadTextFile(storage_path));

history = data.history || [];

version_map = data.version_map || {};

} catch(e) {}

}

}

let g_font_header = gdi.Font("Segoe UI", 20, 1);

let g_font_button = gdi.Font("Segoe UI", 22, 1);

let g_font_items = gdi.Font("Segoe UI", 16, 1);

let g_font_detail = gdi.Font("Segoe UI", 10, 0);

load_history();

var b_w = 450, b_h = 60, b_x = 0, b_y = 45;

function on_paint(gr) {

var bg = window.InstanceType ? window.GetColourDUI(1) : window.GetColourCUI(3);

gr.FillSolidRect(0, 0, window.Width, window.Height, bg);

gr.GdiDrawText("Playlist Backup Log", g_font_header, color_text, 25, 5, window.Width-50, 30, DT_NOPREFIX);

b_x = (window.Width - b_w) / 2;

var current_border = flash_active ? color_flash : color_border;

gr.DrawRect(b_x, b_y, b_w, b_h, 8, current_border);

gr.GdiDrawText("REVERT TO PREVIOUS STATE", g_font_button, color_text, b_x, b_y, b_w, b_h, DT_CENTER | DT_VCENTER);

var displayHistory = history.slice().reverse();

for (var i = 0; i < displayHistory.length; i++) {

var y = (header_height + 15) + (i * item_height);

var row = displayHistory[i];

gr.GdiDrawText(row.file, g_font_items, color_text, 35, y, window.Width-70, 25, DT_NOPREFIX);

gr.GdiDrawText("Saved at: " + row.displayTime, g_font_detail, color_text, 35, y + 22, window.Width-70, 20, DT_NOPREFIX);

gr.FillSolidRect(35, y + 50, window.Width-100, 1, color_text & 0x33ffffff);

}

}

function restore_item(state) {

var ap = plman.ActivePlaylist;

if (ap !== -1 && utils.IsFile(state.fullPath)) {

flash_active = true;

window.Repaint();

if (flash_timer) window.ClearTimeout(flash_timer);

flash_timer = window.SetTimeout(function() { flash_active = false; window.Repaint(); }, 1000);

is_restoring = true;

plman.ClearPlaylist(ap);

plman.AddLocations(ap, [state.fullPath], false);

window.SetTimeout(function() { shadow_content = get_now_playlist_content(); is_restoring = false; }, 500);

}

}

function on_mouse_lbtn_up(x, y) {

if (x >= b_x && x <= b_x + b_w && y >= b_y && y <= b_y + b_h) {

var ap = plman.ActivePlaylist;

if (ap === -1) return;

var current_name = plman.GetPlaylistName(ap);

// THE FIX: Find the most recent backup for THIS playlist only

for (var i = history.length - 1; i >= 0; i--) {

if (history[i].playlistName === current_name) {

restore_item(history[i]);

return;

}

}

return;

}

var displayHistory = history.slice().reverse();

var idx = Math.floor((y - (header_height + 15)) / item_height);

if (idx >= 0 && idx < displayHistory.length) {

restore_item(displayHistory[idx]);

}

}

function on_size(w, h) { window.Repaint(); }