Thank you all for your votes and responses.
Here is my point of view about the topic.
I actually think that the stun time is way too high and think that it should be a bit reduced in Rage mode. I did not know that it's reduced already, but a little more would not hurt. About 10-30 % would be better, too much makesJason too OP.
I agree with @AldermachXI suggestion to reduce chances for a stun in Rage mode. Jason is supposed to be more dangerous when he is pissed off. Keeping the part with knocking counselors from his grip I also agree with.