Yessven, yes it would work for some where they don't need changes at short notice. What percentage of travellers change?? I don't know??

However, where the employee (pax) has to change the booking at short notice (like GibSpmuh's personal example), there may be limited or no availability on those fares, have to pay the $27.50 re-booking fee plus the additional cost to the next available fare basis (which might end up being K anyway, where such short notice exists it may even be H, B or full Y).

I suppose it depends on the circumstances - but that's the reason I go to K from the start like GibSpmuh, Willyroo and others.