Why angled-deck standards follow aircraft design

Would a non-declining British Empire standardize a three-and-a-half-degree angled deck on successive supercarriers?

Only while it suited the aircraft in service; later aircraft requirements would drive any change in angle.

A three-and-a-half-degree angled deck might remain suitable while a navy operates one generation of aircraft. As landing speeds, sizes, and handling needs change, operational feedback would determine whether later supercarriers retained or increased the angle.