Found an RTA setup for Knuckles! Jump at the second to last frame possible then at the usual position after 5 rotations. Bit slower than the Sonic one due to it needing an extra rotation, but it's still enough to get 0:14​. Next up, the reentry clip, and hoo boy. You'll need to wait out the boundary lock like usual, then a frame perfect glide to clip into the floor. Once you're climbing in the wall, press down to enter the SB3 transition.