one such write up is found here
https://www.orrick.com/Events-and-Publications/Pages/New-401-k-Correction-Procedures.aspx
of course, it wasn't really written to handle your particular case in which it was a one time 'extra large' deferral. still, the concept of the employee benefiting by getting the deferral put in by a QNEC and still keeping the comp is the type of windfall this was intended to stop.
and yes, this says the match is still required