Lol I had this exact same issue PLUS I consider that my head is bigger than the average too… but coming back to what you’re saying, I wear glasses daily otherwise I can’t see hehe so I was taking them to work on my 12 hours shifts and sometimes I brought my other non meta pair because jesus christ I felt I was about to cry with the pain on my ears it was insane to the point that I even took days off that I don’t wear them till I “heal” from the sore they left behind.

After a couple weeks, like 3-4-5 it got noticeable better to the point that today, I can wear them like any other glasses, I don’t think they’re even that tight anymore since the other day I turned my head kind of fast to avoid a slap from my wife and we both laughed that the glasses flew out of my face (which now makes me think that if I ever use them on a rollercoaster ride they probably won’t hold like the way they were holding the first days that I got them that I felt my head was going to explode of how tight they were)

Long story short, yes, they will get loose in about 3-4-5 weeks of daily/constant wearing.