How can I use the same TMSFNCStylesManager1 from Form1 as a global one for all forms, or do I have to define another Form2->TMSFNCStylesManager1, Form3->TMSFNCStylesManager1 for each new Forms and initialize them all separately when changing the STYLE?
Right now, there is no global style manager, so you'll need one for each form separately. We'll look into creating an application styles manager to style all forms at once.