Changes required to the AC4BFSP.exe file to enable borderless fullscreen gaming
For details on these instructions see https://defuse.ca/online-x86-assembler.htm
As long as github allow it, here is a zip file which includes the patch for quick use https://github.com/user-attachments/files/17745242/aciv_borderless_patch.zip
These instructions set the width/height to 0 which forces the game to re-calculate the screen size at the start.
Aswell as settin the global IsFullscreen byte (0x2ac07d3) to 0