I had a similar experience. I quit my job as a SWE at Google and built a hardware product on top of the Raspberry Pi.[0]
I don't really have anything helpful to add, but I relate a lot to all of the gotchas you encountered. Shipping a hardware product made me appreciate software so much more, especially SaaS products where you can ship a fix immediately.
With hardware, it's painfully easy to make a mistake and not realize it for 3-6 months. And by that point, you have this whole manufacturing pipeline you have to halt and unwind. And with overseas manufacturing, tariffs, and shipping costs, you can't even unwind some of this stuff, and you just end up with useless material that you paid 5-6 figures for.
We're definitely spoiled in the software world with the relative ease of fixing bugs.
[0] >>23927380