I’d be worried too. Nitrous on top of a stock turboe’d car with the stock ECU rarley works well. In fact, there is no way that I’d do it w/o being able to check/pull timing.
If you are going to do it, get a REAL wideband that you can use with leaded fuel (FJO), tune it to around 11.5 A/F on the bottle, and use PURE C16. Say a little prayer too…