[Thor]

I think its good and fair that max minutes to bust is based on level, it's more logic to me.

Ans I also wonder what would be the point to have a 1-5% chance to bust some1 out.

And I never saw any1 with more than 300 mins stay in there for more than 10 mins, unless a ton of people tried and failed to bust them. The exp at that point is too attractive for any1 that can do it to not try.