I'm not in NJ, I'm in NY, I file IT-201 where taxable pension (incl. foreign) flows from form 1099-R to line 10 and then automatically deducts up to 20K (pension exclusion) on line 29. That's why is so important for me to file 1099-R so i don't have to mess with other income. I don't think it's possible to manually change line 29 on IT-201.
In NJ the threshold amount is not pension > 150K , but income. You can exclude some pension income if your total income for the entire year was $150,000 or less. You can check it here:
https://www.nj.gov/treasury/taxation/njit7.shtml
