I strongly recommend that you do not try to strop a Scandi grind knife with a belt - unless the belt is laid flat on a hard surface.
In many bushcraft books it is suggested that you can use a belt to strop a knife by attaching the belt to a tree, for example, and then holding the belt under tension. This does work to an extent and is perfect for a convex grind knife NOT a scandi. This is because you can't get enough tension in the belt to stop it from rolling round the edge of the knife as you strop. So with a scandi this would eventually turn it into a convex (in an extreme case) - in practice it means that you will be blunting the edge a little by this method.
That's why I say that a belt is ok on a flat surface - that way you do not get the leather curving round the edge in the same way as you would if it was under tension.
Give it a go and see if you get a better edge doing it this way!