Sorry to hear about the first Ioniq but glad to hear it hasn't caused you major headaches overall. In all honesty you haven't missed much haha. we don't know that much about the BZ yet aside from estimates and what it looks like.
Are there any specific specs or features you want Toyota to put in the BZ?
No headaches at all. Insurance for the win

Things happen, no big deal. Cars can be replaced.
It's no secret that Toyota focuses on the important things with their vehicles, but I think they could definitely invest in better technology... actually, invest might be an overstatement.... I think it just needs some refinement.
Since the RAV4 Hybrid is only a couple of months old for us, I find myself comparing it to the Ioniq often because there are things in the Ioniq that are just simply better. Specifically:
- The head unit. Just using CarPlay is a smoother experience, but the overall GUI on the Ioniq's head unit is clean, modern, seamless to use, and just looks great. The head unit in the RAV, while usable, seems like a slightly more updated version of what was in my 2014 Corolla, and that wasn't particularly good either.
- Speaker system. I paid extra for the Tech Package on my RAV4, specifically for the 11-speaker JBL system. The Infiniti system in the Ioniq, which comes standard on all models, is far more balanced and sounds much cleaner than the RAV. Let's put it this way: in the Ioniq, I leave the EQ flat and it sounds great all the time. In the RAV, I need to drop the midrange significantly, raise the treble a few notches, and raise the bass a small amount. Sometimes I find myself making on-the-fly adjustments too. In my own honest opinion, a good speaker system should sound best while the EQ is flat -- unless you have your own preferences of course, but flat should be as the artist intended, and the speaker system should deliver that.
- Driver assistance. I'd say the Ioniq and RAV function almost identically, except I cannot drive with the Lane Tracing option turned on with the RAV. I find myself fighting the steering input from the RAV so much that it just needs to be switched off. It never seems to be satisfied with where it is, and I end up correcting slightly left and right to stay centered when the RAV wants to go the other way. However, with the Ioniq, I never lose confidence on highways when it tries to keep the car center.
At the end of the day though, these are niceties, not necessities. What I really want at the end of the day is longevity and low total cost of ownership. When I buy a BZ4X, my intention is to run it in to the ground and see if they can maintain their reputation for well-maintained cars that can last for 20 years as Toyota is known for, just like I'm doing with my recent RAV purchase. Other than that, I want to see a
real-world range at a minimum 400km and all-wheel drive. I don't care about having huge amounts of power output... the Ioniq has an 88kW motor and it drives quick enough to 130km/h thanks to the electric torque (even though I'm usually a 115km/h cruiser). And assuming I purchase a first year, first generation model, I just want the usual support that I know Toyota provides if there are any issues discovered post-release.