QB64 Phoenix Edition v3.11.0 Released!

[bert22306]

&HFF&& is 256.  Will always be 256.  Can't be anything but 256.
&HFFFF&& is 65535.  Will always be 65535.  Can't be anything but 65535.

&HHFF% <-- integer,so 256
&HFF%% <-- byte, so -1
&HFF~%% <-- unsigned byte, so 255

No ambiguity and it's 100% future proof and will always give you the same result no matter where it's encountered.

Why not use it, once you realize that it may become an issue for you at some point in the future?

Right you are.  I have to train myself to do this consistently.