Hi Andrew,
Would you be able to point me in the direction on what the steps are to make my key on a new layer per your advice above? I just googled creating track matte/alpha but do not see anything that would follow your advice to make a key’ed layer into an alpha.
If I am reading this right it becomes a 3 step process. Key the subject, make layer into track matte and then use hue/sat to fix spill.
Would the alpha work if the subject moves alot?