I bought a 4x8 sheet of 3/4 inch plywood, trimmed it down to 45" wide, and glued the 3" strip on the front side, so the center doors are hanging off 1-1/2" wide plywood.
Doors are crazy expensive right now, I just added biscuits to the bifold doors and glued them to make 24" doors.
Thanks for the suggestions posted earlier. Shoutout to 'look' especially.
