Pros
As much overtime as you could ever want. Your mechanical aptitude will increase dramatically if you apply yourself to the role. Skilled and competent people are rare due to the working conditions making others stay away, so if you are an exception you will stand out. While TSMC started from a horrible position on safety, they are actually improving quite a bit over the months. I am actually quite impressed on how they adapted to this environment. Management may seem asleep at the wheel but they genuinely care about improving the situation. The biggest issue they are dealing with is the multinational cooperation required to make any of this work.
Cons
You won't want the overtime. I hope you didn't have a life before this because you can make your whole life revolve around this. TSMC is a downright dangerous place to be putting tools into, even if they improve dramatically. The pay is not great, and it is not likely to get any better. Also, unless you stand out from the crowd of mediocre contractors you will not be hired on. You may receive a pay CUT from being hired on compared to the contractor.