I've only done a few positions, and I'm not necessarily a fan of all of these players (I do like all of the DE's, though), but here is the list that I have. I didn't include any players who are 3 years out of HS as I don't know if they'll have their degree. All of these players are in their 4th or 5th year out of HS. Safety has definitely been the hardest position to find quality players who could grad transfer. LaMiles Brooks is a solid player and someone I'd want ND to go after if he hit the portal, but after him there's a drop off based on the film I've seen and what I've read.
Quarterback
Michael Pratt (Tulane)
Cam Rising (Utah)
Will Rogers (Mississippi State)
Hudson Card (Purdue)
Brett Gabbert (Miami OH)
Grayson McCall (Coastal Carolina)
Kurtis Rourke (Ohio)
Wide Receiver
Will Sheppard (Vandy)
Jahmal Banks (WF)
Jeremiah Hunter (Cal)
Isaiah Williams (Illinois)
Ja'Mori Maclin (North Texas)
Taylor Morin (WF)
Defensive End
Jasheen Davis (WF)
Kyle Kennard (GT)
Nelson Ceaser (Houston)
R.J. Oben (Duke)
Jereme Robinson (Kansas)
Antwaun Powell-Ryland (VT)
Safety
LaMiles Brooks (GT)
Bud Clark (TCU)
Beau Brade (Maryland)
Craig Woodson (Cal)
Jacquez Warren (Miami OH)