Hum, my guess is that it is glue, not thermal grease! It is very dense inside the head host, and it can even be seen next to the MCPCB.
I believe that it is some sort of glue or silicone, maybe. It may take a while to take it out , in case of doing some mods!! :expressionless:

EDIT: And thanks for your words :wink: :blush: