"This enables you to get arbitrary updates to your orders reliably, irrespective of when they happen (COMPLETE, CANCEL, REJECTED, UPDATE). An UPDATE postback is triggered when an open order is modified or when there's a partial fill. This can be used to track trades. "
Regarding this, when the user places the order from web UI manually and the order is in OPEN or VALIDATION PENDING, RMS Check pending etc states, will the postback url is triggered ?
Also, does the order updates come in order. For example, sometimes I found that order updates over websocket is coming not in order. Like the order complete update comes earlier than partial fill. Is it the same with postback url ?