...I would advise the Same als Avenger.
Not long after my own upgrade I had the following scenario:
After departure on our way home again we had a decreasing indication of the pressure of the flight crew oxygen bottle. We were already a bit suspicious as the indication on the turnaround was quite a bit lower than when we left home in the morning. No decrease in pressure was observed, all masks were checked, and pressure was above minimum for dispatch on the ground during turnaround, so we went. A decision I regretted, as now -due to the differential pressure- the indication started to decrease and we had an inflight oxy leak on our hands. I never received any guidance on best practices of this or any requirement of flight crew oxy pressure INFLIGHT. But my gut feeling told me that it might be handy to have at least some that stuff during our 2,5hr flight at FL370. So I agreed with my FO that we would divert enroute when the value would reach below a certain value. After that I checked all the masks again and found a light hissing sound on the LHS jumpseat mask. Relief came when I was able to disconnect the hose and stop the leak at 230PSI, only 30 above our minimum agreed value. The hose had a small puncture close to the mask connection.
...for your entertainment.