It seems as if the Delta Seconds for the Event Tick does not factor in the tick interval when calculating itself, which it seems like it should. Steps to see what I am talking about:
Create the same blueprint setup as I have here (Mine is in the level blueprint):
http://puu.sh/kxBXQ/866aa43a60.png
Now if you play the game, you should see that the print string is counting up accurately with time. Now if you go into the Class Defaults and change the tick interval to something like .1 and play, you’ll see that it is no longer counting up with time. What I think should be happening is that the Delta Seconds should be adding .1 every tick with the new tick interval, but it just adds the frame time in seconds.
I’m not sure what the term ‘Delta Seconds’ means, but I think that the event tick should output the time since the last tick in the current blueprint, not the frame time in seconds.