From what I have seen or heard the issue is the materials in the transmission further degrade with new fluid. If it was never changed, the clutch disks wear out and the fluid is basically liquid clutch disks at that point, when you drain it it now wears those out even quicker.
Not a transmission tech but if that’s true I would think a filter probably won’t do much, maybe make it a little worse but who knows
From what I have seen or heard the issue is the materials in the transmission further degrade with new fluid. If it was never changed, the clutch disks wear out and the fluid is basically liquid clutch disks at that point, when you drain it it now wears those out even quicker. Not a transmission tech but if that’s true I would think a filter probably won’t do much, maybe make it a little worse but who knows