From the sounds of it, Franklin is giving him complete control of the defense, which is something Day didn't. So I imagine you'll get the full Knowles experience.
Knowles came in super aggressive in 2022, blitzing all the time. That led to some massive defensive breakdowns against Michigan and Georgia among others, which prompted Day to force Knowles to dial it back. Then the defense got a bit too relaxed, which led to the 2024 Oregon debacle. Day intervened again, which is what reportedly caused the rupture. The defense that we saw during the playoff was a hybrid of Knowles system with the changes demanded by Ryan Day. It worked beautifully, but understandably Knowles was upset and was actually in contact with Oklahoma shortly after the Tennessee game in late December.
We only saw the unfiltered Jim Knowles defense for a short period of time, so the experience you all get will probably be quite different (for better or worse -- who knows) than what we got.