MY release is almost instant too. BUT there is a brief moment at full drew before release.
When I first came over to the greener side of the fence, i was leaving alot of shots through a compound behind. IMO I was really good with a compound (all humility aside). I'd draw, hold, find my sights, breathe, shoot. Arrows were always next to each other.
As soon as I started shooting trad, I'd draw and let her rip. It was like I just shot for the enjoyment of shooting, not hitting a spot, just the target. arrow after arrow, draw and shoot draw and shoot.
As soon as I noticed this, that I wasn't staring down a spot, I wasn't take care arrow to arrow to hit that spot, I realized I had to change something.
NOw, when I get to full draw there is a split second where I get a sight picture of the arrow and the spot, and then the arrows gone. MY groups shrank a ton. Just MY experience, I have to be mindful of arrow to arrow actually trying to hit something with good form and release, though the whole process really takes very little time. Without I could shoot 100 arrows and never even think about anything, just flinging arrows.