My reference for filing rules is (https://www.njportal.com/Taxation/NJ1040/Content/Docs/Instructions/Current_NJ1040Instructions.pdf).
There is even language about encouraging e-filing, e.g.:
"E-File Mandate. Preparers that reasonably expect to prepare
11 or more individual resident Income Tax returns (including
those filed for trusts and estates) during the tax year must use
electronic methods to file those returns if an electronic filing
option is available. A tax preparer is liable for a penalty of $50
for each return they fail to file electronically when required to
do so."
