So the biggest possibility seems to be the drop in pressure due to a low bottle.

I'll get it filled and have it dyno'd again in the near future. Will also raise the activation RPM to ~5k.

I looked into the Nano system and on the surface it seems pretty nice. I'm just not sure if the cost/hassle would be worth it for someone that will be using the nitrous very sparingly/casually. Seems like I can accomplish the same thing by just keeping my bottle topped off. Looks like it would be a nice addition for someone that's carrying a bigger shot though.