Yes, the real 65w charger can charge oppoace charging protocol is the same.
But to make sure that your charging cable to match the charging port of the OPPO mobile phone can be charged, no matter how much your charger is fast charge or flash charge, he OPPO mobile phone as long as his charging port is matched with the head of your charging cable, you can charge it. The above answers can help you
Yes, the phone has downward or upward compatible parts, but the charging power is not too fast