I would send this video to people who work at Embedded focused companies you're interested in working at, especially team leads, find them on LinkedIn and message them, worse that happens is they ignore you, you lose absolutely nothing as a result though!

The best way to get past HR is to go around them and straight to the team lead if and when possible. I wouldn't have my current job as a Software Engineer if I had to go through HR first.

I would also definitely put this in your resume.

Funny, I was an ee major who wants to study more chemistry. At any rate, you obviously have the talent to do embedded software. Id advise bypassing HR whenever possible, as the other poster noted, as well as doing more deep dive self study projects. You'll get there in no time.