Trouble Accurately Logging Several Back-to-Back SMS Delivery Intents for Android

Question

I am developing an android app that rapidly sends multiple SMS messages almost simultaneously to the same number (Please note this is for research purposes). I need this app to also track it's delivery intent, which I do by adding a bundle containing the information I want the intent to carry. The problem I am running into, however, is as follows:

• If I use no pending intent flag (aka 0) or FLAG_IMMUTABLE, the bundle value always remains the same as the first message sent and I get a dump of all the messages delivered.
• If I use FLAG_UPDATE_CURRENT, I get a bundle value that updates sporadically/randomly (multiple intents contain the same bundle value), and I get a dump of all the messages delivered.
• If I use FLAG_ONE_SHOT, I get the accurate bundle value assigned (the value as it is meant to be received) BUT I only get a dump of a very small amount of the intents, and that amount stays small(~1%) even if I happen to send over 1000 messages back-to-back.

Here is the portion of the message sending method responsible for sending the SMSs in MainActivity:

int z = 0;
for(int j=1; j<=messageCnt;j++){
    try {
         Intent dI = new Intent("SMS_DELIVERED");

         Bundle b = new Bundle();
         b.putString("MSGNUM",Integer.toString(z+1));
         dI.putExtras(b);
         dI.putExtra("MNUMSTR",Integer.toString(z+1));
         PendingIntent deliveredIntent = PendingIntent.getBroadcast(getApplicationContext(),0,dI,PendingIntent.FLAG_ONE_SHOT);
         deliveredPendingIntents.add(z,deliveredIntent);

         SmsManager.getDefault().sendTextMessage(phoneNum, null, message[z], null, deliveredIntent);
         b.clear();
    }
    catch (Exception e){
        StringWriter sw = new StringWriter();
        PrintWriter pw = new PrintWriter(sw);
        e.printStackTrace(pw);
        crashTrack.add((Long.toString(System.currentTimeMillis())).concat(",").concat("'").concat(sw.toString()).concat("'\n"));
        //reset all incremental value back one for proper repeat
        j=j-1;
        continue; //jump back to for loop and reattempt send.
    }
}

Then, wherever I want (whether it be in a new app or in the current app), I put the following to register my receiver class.

//Create Broadcast receivers for sent and delivered intents
SmsDeliveredReceiver SDR = new SmsDeliveredReceiver();

//register the receivers
registerReceiver(SDR, new IntentFilter("SMS_DELIVERED"));

And finally, my broadcast reciever class for the intent, SmsDeliveredReciever:

public class SmsDeliveredReceiver extends BroadcastReceiver {
        protected static int sentCount = 0;

        @Override
        public void onReceive(Context context, Intent dI){

            /*File delivDumpName = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS),MainActivity.dateTime.concat("DelivDump.txt"));
            File delivfailDumpName = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS),MainActivity.dateTime.concat("DelivFailDump.txt"));*/

            Bundle bundle = dI.getExtras();
            switch (getResultCode()){
                case Activity.RESULT_OK:
                    if(bundle!=null){
                        String msgNum = bundle.getString("MSGNUM","0");
                        MainActivity.delvDump.add(Long.toString(System.currentTimeMillis()).concat(",'Msg ").concat(msgNum).concat("'\n"));
                    } else {
                        MainActivity.delvDump.add(Long.toString(System.currentTimeMillis()).concat(",'Msg ").concat("Number Unknown'\n"));//Integer.toString(sentCount)).concat("'\n"));
                    }
                    break;
                case Activity.RESULT_CANCELED:
                    if(bundle!=null){
                        String msgNum = bundle.getString("MSGNUM","0");
                        MainActivity.delvDump.add(Long.toString(System.currentTimeMillis()).concat(",'Sms Failed to Deliver.',' Msg ").concat(msgNum).concat("'\n"));
                    } else {
                        MainActivity.delvDump.add(Long.toString(System.currentTimeMillis()).concat(",'Sms Failed to Deliver.',' Msg ").concat("Number Unknown'\n"));//Integer.toString(sentCount)).concat("'\n"));
                    }
                    break;
            }

            /*MainActivity.writeFiles(delivDumpName,String.valueOf(MainActivity.delvDump));
            MainActivity.writeFiles(delivfailDumpName, String.valueOf(MainActivity.delvFailDump));*/
            sentCount++;
        }
}

Note that the exact same thing happens for the SendIntent. I've read all of the Google Android SDK Docs, and stackoverflow so far has provided answers that only work for alerts/alarms and not SMS intents, where the only existing tutorials and forum entries for SMS are single-send SMS. And no, I am not trying to send a multi-part message.

Desired output:

1. All SMS delivery intents should be captured in the broadcast receiver
2. Each intent captured must output its own unique message association number via the bundle.
3. The amount of intents captured should equal the number of messages successfully sent (yes, I do have a way to check whether the message got received or not)

Is this desired output even possible, or am I asking too much out of Android? Whether the receiver is a separate app or not does not matter to me, though it is preferred if its a separate app.

Note: Everything in the app is functional and error-free except accurately tracking/logging the sent/delivered intents.