I'm not following, what is the disadvantage to running weisco? You should ALWAYS warm up your bike wether using cast or forged pistons, forged pistons just expand at a different rate than the cylinders (which are cast)...Other than that I see absolutly NO disadvantage, they are stronger which is most important part of a piston, and lighter weight as well (next most important factor). Since when is cast stronger than forged?
Don't port your pistons. theres not much reason to, you might get another HP or two but it will likely make them weaker, they already have the necessary size holes and there is a reason for this...Look for another way to add the HP.
Also not sure I'm following the logic on having to have a stroked motor to run weiscos, so if I have a non stroked Cub I should stick with forged? Even on a ported bike I would run Forged pistons, as your already making nearly double the power from the factory. Makes no sense to me! I ran stock pistons for 3 years and weiscos for 3 years on my ported bike, I have not had problems with either setup in terms of reliability.
I read about some pisons made in some part of europe that were also forged and had some special Molybdenum Bisulphide coating or something but I don't know much about them (not even the name).