S9+ Flash Firmware to V10 in order to update /e/ OS to Q

All it takes is the right flash/install method :))

I am absolutely sure:
Installing the *.ZIP files downloaded by @cornfarmer must not be installed with TWRP. The *.ZIP file must first be unzipped. The resulting files (AP, BL; CP, CSC) .tar.md5 must be installed with Odin v3.14.4 or Heimdall.