The thing with a BSD project is that it is a kernel, a distribution of slightly modified and configured 3rd party applications, and a bunch of 1st party applications.
OpenBSD project includes stuff like OpenSSH, time sync tools, an SSL implementation, and these are very widely used. Are those devices OpenBSD based though?
Similarly with BSD code, you can just use it and you only need to credit it with the code, so lots of OpenBSD kernel code will be in other systems with no user visible attribution. If MacOS kernel contains OpenBSD code, even big chunks, is it OpenBSD based?
With Linux, GPL means its kind of visible when someone is using it, and GPL encourages you not to integrate your software with it too tightly, so you get an obviously Linux based device with proprietary code on the top. With BSD, you can integrate much more tightly, only ever need to give out a binary blob, and no one would know you were using it.
That said, OpenBSD is kind of server oriented, and FreeBSD would be a more popular starting point for a device, but you might well crib OpenBSD for best practices.