All nitrous setups add fuel. If they didn’t, then they wouldn’t work at ALL.
Wet does it through a braided line tapped into the fuel rail (for example) that feeds a solenoid. The noid opens same as the N2O noid, and is metered through a jet like the nitrous.
Dry shot still feeds nitrous through a noid & jet, but it raises Fuel PSI to get more out of the injectors. “Easier” install they say.
For the extra 5 minutes of work, I greatly prefer wet shot. I have more trust in a machined & metered jet then I would in a bump in fuel pressure. But thats personal opinon.
If there were only “nitrous being sprayed into the intake” every single dry kit user would be replacing engine parts after EVERY shot.