If you are away from house during weekday, children going to school during weekday - yes, opt in.

If you work from home, children at home regardless weekdays or weekend  - perhaps opt out.

I think ToU should be better for most households. For 450kWh, you need to use 63% peak for both rates to be equal. Maybe that’s why TNB default to non-ToU since consumers will pay more.

But how do you decide if someone is suitable for ToU or not? Everyone usage differs, someone might be using more power during peak period, obviously for someone like this ToU is unsuitable. Then you have those who rent our their properties where its hard to control tenant usage, and then those using solar.

Maybe there's way to calculate from our bills, but we are not experts so we dont know how complicated it is to implement such a function and how much does it costs. And as always, the costs will be reflected onto the consumers in the end anyway

The fair method would be to convert everyone to ToU so everyone follow the same peak and off peak rate. But again doing this someone who use more during peak period will complain also

I'm fully aware of how to take full advantage of ToU (refer my latest reply above)

My reply is for kopiride's reply that TnB should automatically decide ToU for users instead of us applying manually