I lost mah mind recently and refilled Ye Olde Borg-Warner 1354(?) with a fluid so special, they don't even make it any more:
Valvoline MaxLife Full-Synthetic Dex/Merc ATF (newer version is "ALL Vehicles"... can't trust that, lol...) ... supposedly it will no longer shift-on-the-fly... in fact, it will probably <<eh-SPLODE>> the moment it's engaged!...

... I'll let you know when I get The Dreaded PVH Hubs fixed... and the vacuum lines re-routed... and the shift motor replaced... and...
In the meantime, the M5OD tranny has never shifted better! Took a couple hundred miles for the Valvoline to work into all the synchros and splash up onto the new shifter bushings, and displace remnants of the old ATF with 80k miles on it, but now it's like buttah, up-shifting and down-shifting! No more double-clutch RPM-matching...