Oscillators and Other Synthesizer Features in Garageband?

I was looking at some midi files that used a specific soundfont, and when I assign it the appropriate soundfont, and play it, it sounds like a modified version. They're synthesizer sounds I'm using (famicom/NES sounds). I saw on an old Garageband version that you could change some oscillator effects on the DLS music device, but I don't see that there at all (I'm using Garageband 10.0.1).

Is there an Oscillator feature that allows me to change synth sounds into different waves like sine, square, and sawtooth, and triangle? Maybe other things like attack and decay? (Although those are already in the smart controls for some synth sounds already) Thank you!