not precisely on point for your trans, but I've done work (full fluid flush, filter, mechatronic seals) on my BMW ZF unit... and will do the similar job on my E320 in a month or so.

Similarly, there are tech documents for this (ZF) job indicating a 'need' for (I assume you mean?) an infrared temp sensor to test temp of the transmission. Correct fill level is specified for a correct 'operating temperature' of the trans. Seemed like overkill to me. So, warmed mine up nicely, likely shifted through gears to distribute fluid, then filled to just about leaking out - the recommended level.

...and have never looked back.

Fluid flush and change seems like a very, very good idea for simple preventive maintenance on these units.

__________________
'83 300 SD
'05 E320 4Matic
'06 BMW 530 xi
'68 Triumph TR 250 - The only car I ever loved more than the Mercedes; who needs electricity, anyway? - Damn, why did I sell it?!
'59 Jaguar 3.4 'Le Chat Noir' - Damn, why did I sell it?!

It's difficult to make predictions, especially about the future.
- Niels Bohr