According to this article, grafts are fully secure on day 9.
I recommend everyone read this article and not attempt scab removal until post op day 9. My surgery was complete on Friday at 5 pm Turkish time. I removed grafts on Sunday 6 am turkish time. So technically it was 9 days postop but had I read this article earlier, I would have waited at least another 12-24 hours.
i hope this is beneficial to others