An interesting, yet understated point you make there.
Disconnection times are one thing that PoCo's here are trying to get into line.
We have a Standard disconnection time for all Installations of 0.4 second, regardless of the type of protection, be it HRC fusing or Circuit Breaker protection.
Hence the way we are going now, we are ripping out old Panels that use the old Porcelain fuses, some of which, depending on who last loaded the fuses, can have an Arc time of up to 4 hours, in some cases, they never blow and we get there in our Red Trucks with the flashing lights on top.
Let's face it, these days if you're not young, you're old - Red Green