Instance crashes and rollbacks.

I just lost my first Divine of the league to an instance crash and char rollback.
It was only the mirage instance that crashed.

Its is demoralizing that something can be in your inventory for minutes and still disappear on an instance crash, considering its my 6th char rollback where I noticed I lost something.

Its thoroughly disappointing that it looks like (from a player perspective) everyone (or a few people if it came down to decisions from the top) thought increasing the number of active instances and the frequency moving characters between instances so much wouldn't have an effect.

I cant help but wonder was it "play tested" in ai simulation or on no scale at all?

Next time test parts of it a head of launch.
Introduce a dummy mechanic in a event league (or some time into a normal league, you have the stats to figure out whatever stress tests the most) such as phrecia, make it time limited so ppl rush for it.

In this case it could have entered you into an instance with a reward in it, a few easy mobs and with a chance for a instance to spawn another portal to a deeper instance, thus creating a scenario where ppl are incentivized spawn and move between instances more frequently then normal and several layers deep (as we can multiply league mechanics which spawn instances too).

Or it could have just been an introduction of a reward chest in a spawnable instance that people can spam on command. That would certainly spawn a lot more instances though it might not test quite the same thing, again your stats, you can figure those details out.