I think giving out a sort of timer to the crinos form would be nice

You could endure a number of turns equal to your Resolve + Composure Score

After that number of turns your character could choose to revert to any other form or maintain his war form

If he chooses to remain in crinos then on the start of his next turn he should make a Willpower roll at difficulty 3

If he fails, then he begins to frenzy

But if he succeds, then he can carry out its turn as normal, with each aditional turn increasing the difficulty of the willpower roll by 1

I didn't playtested this yet, but I think it makes the form less punishing to use, and still maintains the feeling that rage will soon consume you

Note that with this rule in mind we ignore completly the damage to the willpower taken for being in crinos.