BIOS updates are always incremental. The only code changed to fix bugs is the code that causes the bug, the rest remains unchanged. The same goes for new features/enhancements, code is added to enable the feature/enhancement, the rest of the code remains unchanged. That's not to say the the code changed or added doesn't create a new problem.
That was the long answer, the short answer is yes all changes up to F4 will be included in F5.