Devotion and reduced cost innates Options

[Simon]

If you have 'Devotion' and a multiclass that gives reduced spirit cost (one of the Spiritual~ classes, for example) casting miracles of a particular sphere, and can buy those miracles at the reduced spirits cost (it's not clear in the Evolution book if you can) do the two combine?

For example;

Spirit Sheild, normally 3 spirits. Character has m/c'ed Spiritual Warden, cost is now 2 spirits. Innates would normally cost 20pts each.

With Devotion, does that become 10pts?

You can't standardly apply casting reduction when buying (or assigning) innates.

Lee