I was shocked to learn that fullscreen mode is no longer supported. I did not notice it because I am still using
Windows XP, with some help from
XP Forever. Please, do not drop this option altogether, for the happy owners of older OSes still enjoy the immaculate beauty of
WinSPWW2 in a distraction-free environment.
In my opinion,
WinSPWW2 must support fullscreen mode natively, as do all decent games. It should not be difficult. Is it legacy code that makes the task so hard? Have you tried emulating the 256-color palette on top of the native 24-bit true color mode instead of forcing an actual 256-color mode? This is how
DOSBox works, and how modern pixel-art games are implemented. Have you considered seeking whatever help other programmers may provide without reading the sources?