It is definitely true that all surgeons have their preferences. I do wonder if a few things are getting confused here. There are two times that bone gets dealt with in these surgeries.
1. The craniotomy--that the hole they cut in your skull to get to the tumor.
2. the Interior auditory canal (IAC).
there are different options for how to replace the bone from the craniotomy. Some use titanium. My surgeon used an absorbable plate system, so that over 6-9 months the things holding the bone flap in place are absorbed by the body as the bone heals, so now I have not metal in my head.
The IAC, as I understand it, gets obliterated during surgery. Because it is so small, the just grind it away. This is where the cement/bone wax comes in. You seem to have confused the titanium plating to replace the craniotomy bone flap with the bone from the IAC. I don't think they ever do that. There may be other products than cement to fill in the IAC after tumor removal. (For me, the harvested some belly fat to put in the IAC, and then covered it all with "bone wax," whatever that is.)
I don't know if I"m making sense, but it does seem in your second point you can the craniotomy and IAC parts combined.