Once yyou are approved as a sponsor and the file is transfered to Islamabad then it should be ok. You don't want to leave while you stage 1 is in process just incase they need something and you are not available to provide them the info. So I would wait until you receive the approval letter from CPC-M. TIP: save your airline tickets, boarding passes, passport stamps etc. as well as all your emails, photos, phone call logs, fund transfer receipts, chats and whatever for future support.
