Terminating safe harbor nonelective contribution

[k man]

is anyone familiar with the substantial business hardship exception for terminating the safe harbor nonelective contribution portion of the plan? client had would like to keep the 401(k) portion of the plan going but in order to do so would need to qualify for the substantial business hardship. there are several factors listed in the code but the list is not inclusive of all factors. i am wondering if there is other guidance. ie. if you use the definition of substantial business hardship in 412 do you also need service approval?