Complain: Completing Nexus is "one-try-only-boss".

With the recent changes in middle of 0.3, every map has a boss. Thats basically a good feature.
With the change to be more casual friendly in 0.2, we can "die" in maps. thats also a friendly feature.
Downside here is, when you die in Boss Fights, the map resets and looses all content.

while this might be an understandable issue, even if I am questioning it. but here is now the the problem:

Every Nexus map for completing has a boss and you need to kill the map boss in order to complete the Nexus task. But if you fail in your first try, its over. The "its a Nexus"-Content is removed and you can no longer complete the Nexus.

Its very frustrating.
Especially, if you acknowledge, that there were so many recent changes that makes "dying" less of an issue.
combined with the situation, that you need to hunt for corrupted zones, and sometimes even dont find any, its not very smooth gameplay.