Yes. Having watched it 3 times myself, I noticed that.I'm watching Hamilton again because I'm like a 4 y/o child who can't get enough.
This time I noticed that Miranda has what looks like a clumpy chunk of hair on his hairline. I thought it was some hairspray chunk or something. Then I noticed that all the guys and women who have longer hair have the same thing. That got me thinking it might be a fancy lapel mic on their heads. Turns out that's exactly what it is and all of the actors with hair wear them. Interesting. Apparently it's a Broadway thing. I've never seen them worn like that before.
Here both Miranda and Soo are wearing them.
View attachment 7045
I always look for those things. I spend half of my time at those shows checking out the sets and production stuff. It’s fascinating figuring out how they make shows happen.