I agree. If it states it meets or exceeds Kubota UDT, you are fine.
Super UDT from what I was told has a lower pour, shear stable, more friction mods (adds) and can be used in more then diffs etc.
But of you look online at Kubota's stite they state:
"Transmission Oil (KUBOTA SUPER UDT *1):
(I bolded some areas)
KUBOTA Original Transmission hydraulic fluid. The oil used to lubricate the transmission is also used as hydraulic fluid. To insure proper operation of the hydraulic system and complete lubrication of the transmission, it is important that a multi-grade transmission fluid be used in this system. We recommend the use of KUBOTA UDT or SUPER UDT fluid for optimum protection and performance. (Consult your KUBOTA dealer for further detail.)
Do not mix different brands together. "
From what I read and printed awhile ago, The recommending of both is new.