When do you check your oil level and replenish? It is critical to chk the level as soon as possible after shutdown and no longer than 15 min after shutdown as stated in the FLM. The oil drains back into the MO1 so the level you see is not representative of the oil in the system but only in the reservoir. If after shutdown the level is on min or just above it is correct and do not add oil afterwards even if you can see no oil level in the side glass-if uncertain do a ground run to oil t 65 degrees and shutdown and check or open the spout and normally if level is ok you will see the oil.
She is dumping the excess oil out the breather to prevent over pressurising the system. Continuous over filling will lead to the mag seal in the MO1 and MO5 starting to leak.
Hope this helps