Not all engine ice releated issues are due to ice crystals at high altitude. Many are due to low power on the ground or flight idle, building up ice in the LPC and then later shedding into the HPC stage 1 blades (spinning much faster). The consequences of these bent blade may not be felt until sometime later in the flight where the engine compressor surge margin is impacted.
Many engines in some fleets even go for a long time with such damaged blades and are found only during overhaul in a shop.
Of course unlight problems are felt to be instantaneous to a shed.
Like I said earlier, the engine response is predicated on the Fadec logic and bleed locations to recover from rare events. That and where the probes are located sets the difference between engine models as well as the time spent poking around the sky in the vicinity of ice crystals.
I suspect that both Boeing and Airbus are going to spend more effort at defining their intended icing envelopes so as to ensure that their purchase specs on the engine aim at recovery tolerance shoud they find themselves in an icing environment not covered in the certification specs.
This is neither a Boeing nor a GE problem, it's and industry problem and need be addressed outside the scope of the current engine certification regulations for the ttime being.