Oil consumption is a maintenance issue and rarely a safety issue beyond being an indicator needing other parameters to be considered (vibration, Oil temp, EGT)
Oil leakage can be a flight safety issue if you don't know where the oil is going. I've seen some operators who added quarts of oil at every major turn, figuring that next week they could get the engine changed out. Only they never made it to next week before they blew a turbine out the side of the engine. On the other hand when I was aboard one of these operators on a long haul over water, the pilot got a low oil light and turned back. Sure enough the ground crew pushed a stand up to the engine as we, the passengers watched, and there on top of the stairs was a full case of oil.
Ah but it was good news, they poured in the oil and motored the engine and presto out came the oil from a blown CSD gasket (external from the engine). That confirmed where the oil had gone! So they replaced the gasket and we were off again for our flight. Had they simply replaced the oil, I would have gotten off (I did chat with the capt about this
Most of the oil consumption is in fumes out the breather and thankfully the pressure balances do a good job of keeping the oil out of rotor-disk cavities. The problem is when wet oil finds it's way into a rotor disk cavity where it is often hot enough to light it off.