Recommended is 220-350
I wouldn't say it couldn't work lower but, my main concern would be the nem not being happy roaming around the tank looking for better light stinging everything in the happy place search.
What type of light set up do you have?
May be possibly at add suplement lighting to get your par levels in range?
180 imo, is a little risky while some nems could probably adapt to it, it would make a big difference if that 180 par you mentioned would be limited to a specific spot in the tank such as a hot spot? Or is that all acros the tank? (Nems aren't likely to stay where you want them - so if that's a hot spot area it would greatly increase the risk of it not being a good idea)
Also you clearly said under 180 if that's the peak hot spot area I would say no, consider lower light nems like rock flowers they come in cool colors. There may also be other nem options that I'm not aware of to increase your options.
They may even be able to survive that in par, yet I wouldn't see them being happy and thriving.