The pending approval is misleading. The first initial document check is a quick check over. It then goes to pending approval. From that point it can go into request more documents, approved or rejected
make sure TM30 is updated. You can apply online for the 90 days I think 1 week before the date comes up so it will give you time too see if it is accepted or not. If rejected you have to do again in person then it will be up to you to extend on that day or go back to immigration when the extension date is
Second time can do online. Or if you go the next time you can also ask for a residency certificate so you can open a bank account or use too get Thai driving licence