The ZF9 transaxle is an inherently flawed design that has had issues in every vehicle it's been installed in. The software tweaks only mask the poor design.
I would have to disagree with your analysis of the ZF9 tranny.
Nearly all auto manufacturers have had some issues with their automatic trannys.
Honda had far more issues with their in-house automatics back in the early 2000s.
They were rebuilding trannys and shipping them to dealers at a rate of 500-600 a day for a few years between 2003-2012 to take care of the failed units. Needle bearing failures was one of the main issues. The ZF9 has not had anywhere near that amount of failures.
But the ZF9 definitely had issues though when it was first introduced and installed in Chryslers and Jeeps back around 2014 and Hondas in 2016. But by 2019, Honda (and other manufacturers) made small mechanical and software changes to rid the majority of issues. Driving a 2016-18 MDX compared to a 19/20 is a world of difference. I had a 17 MDX and now a 20 and my 20 is far smoother and has had absolutely no issues in over 20K miles.
Do some people still have issues …… yes. But they have been greatly reduced.
And to call the ZF9 a flawed design is not really accurate. It is a very unique tranny that utilizes two dog clutches that make shifting from 4-5 and 7-8 feel more abrupt. Earlier versions also had a rough or slight delay when downshifting. But it’s wide range of gearing gave excellent acceleration and great fuel mileage, especially when it finally gets into 9th gear. Many people report over 30 mpg on the hwy (I got over 30 on a short 175 mile trip into AL earlier this month). But the ZF9 just doesn’t shift or act like a regular automatic and many people don’t like it because of this.
Honda still continues to install them in the Passport, Ridgeline and Pilot while Nissan now uses it in their new Pathfinder and Infiniti QX60.
Other manufacturers that have used them or continue to use them …. Alfa Romeo, Jaguar, Land Rover, and Fiat.
I also have a BMW M235i with a ZF8 tranny. Really fun car to drive and it shifts great … no issues. It doesn’t shift like the ZF9, it’s a more traditional automatic, more linear but rock solid. I wouldn’t say it’s any smoother than the ZF9 though.
The ZF9 is just a different feeling tranny and definitely had some startup issues, but in my opinion gets a bad rap now.