I've worked in product management for the past 10ish years, predominately working on products that are a combination of hardware + software, hardware that's connected to the cloud. SaaS and ecommerce product management is written about to death while I've struggled with finding hardware product management content (I still do) which is quite isolating. The closest thing I've been able to find is Industrial Design content.
Books:
Build by Tony Faddell (not really an ID book, but talks about building physical products and businesses)
Some of the people I follow on Linkedin:
https://www.linkedin.com/in/ansondotdesign/
https://www.linkedin.com/feed/update/urn:li:activity:7168968...