Southern Hotrod LLC offers upgrades to various factory transmissions for reasonable prices with transparent processes. For about $4600-4800 in 3-5 days after receiving your 722.9 transmission, they will rebuild it into a "war viking" using upgraded components.
They note perhaps obviously that the transmission must be calibrated to the car. I would guess with STAR or tuning. I'll ask and hit them with some questions. For now though suffice it to say Southern Hotrod should be on your radar (like Weistec) if you want to upgrade your transmission.
Southern Hotrod is Veteran owned, based out of the fine city of New Orleans. Notably the founder Edwin P Gregory III is a Mercedes Master Technician, and previously worked on F-14 Powerplants.
Tuning enthusiasts may appreciate SHR's instagram.