timing retard for nitrous .

It wont know if your locked out or not, but it may end up going into a critical area of spark timing where something bad could happen if it retards past where its supposed to go. a retard is always hardware based ie. you have to advance the locked out distributor where no box retard would be where it needs to be on a standard advance curve, you cannot add advance. The added advance that may be shown on the controller is not a true advance, its just less delay from the box itself.