I know people on here swear by Motul Gear 300 which is GL-5 but my transmission felt like complete trash with that fluid. It was like a 1990s domestic. I have had great luck going to Red Line MT-90 which is GL-4. What I remember from looking for answers was that GL-4 was better than GL-3 in every way but GL-5 is fundamentally different and can attack yellow metals.
https://bobistheoilguy.com/forums/th...vs-gl-5.37720/