You can read/write/delete the macOS user default values on the command line by using the "default" command, e.g.
$ defaults read ru.keepcoder.Telegram
{
kIsMinimisizeType = 0;
kSendingType = cmdEnter;
kShowEmptyTips = 0;
"window_saver_TGUIKit.Window" = {length = 356, bytes = 0x62706c69 73743030 d4010203 04050607 ... 00000000 00000108 };
}
So you can delete all the values for your app using your bundle identifier