Yes, but you can't switch to the 95 map until all the meth is out of the system, otherwise you air/fuel ratios will be way out. Same the other way round too, if you have half a tank of 95, you can't just lob methanol into it because you won't know the exact quantity of petrol in the car. And then your air/fuel will be way off again. So you need to start with fresh tanks of each if you get me.
With NF, you can just downgrade to the 95 map at your convenience, even half way down the road. If you are mapped for 1/3 of a bottle per tank and stop in to the petrol station, then you can throw that 1/3 bottle in the tank regardless of whether there's NF in the system or not already.