On
some cars having a dry shot of nitrous is fine because the car's computer controls a combination of fuel and timing parameters. So if the mixture is lean, then the computer adds fuel, and/or pulls the timing.
The Viper doesn't have a knock sensor, and by itself won't compensate by adding fuel.
So if you are running a dry shot (even a relatively small one) it means that either the car will need to be tuned to run rich for normal driving (which would be fine when the N2O is used), or it runs lean when the nitrous is used (not good).

There is some tolerance when you use a small shot, but I wouldn't risk it.
Especially considering that just adding the fuel makes it relatively safe.
Another possible solution might be using Sean Roe's VEC-2. He has set up some of his supercharged cars with a small dry shot, with the VEC-2 increasing the fuel flow and triggering the nitrous. That could potentially be a nice solution for handling a small dry shot.
And in addition you would get the extra tuning advantages of the VEC-2.