The handle ties would be a major problem in commercial work, many typical office cubes (modular office partitions) are designed to be fed multiwire (3 hots 1 Neutral).

It would basically put a whole section out when one person plugs in a heater for their feet.

LK I am sorry for your friend that lost someone, but I still do not agree with handle ties.

Would you also have the NEC say you can only have one circuit in a box?

As in two or more two wire circuits.

My views may be bias as I install and maintain multiwire circuits almost daily, and I do not see any more problems with these than 2 wire circuits.

It is difficult to actually get 208 or 240 volts when the neutral is lost, this would require a dead short on one side of the multiwire circuit and the loss of the neutral.(I will admit I have seen surge protectors taken out by lost neutrals)

It is not unusually for us to have an entire 42 circuit panel wired with multiwire circuits (42 hots 14 neutrals) as that is what the office furniture requires.

JMO, Bob

Bob Badger
Construction & Maintenance Electrician
Massachusetts