When shooting interiors with the Osmo, is there any way or technique to not make the Iris open and close when panning across windows and the ilk?  I have tried setting the Iris for a fixed F Stop, but then either the window gets blown out, or the rest of the room looks dark.  Does anyone move the center range for auto iris around as they are walking around so that it maintains a regular Iris?  I have ND filters for it, but won't that just have the same Iris open and close effect only cutting it down a few stops?  Or is the only option to gel the hell out of the windows and get your shot that way?

You are right to lock the camera exposure. You will however need to decide which is more important, the window or the interior. Either put neutral density gel on the window or light the room. Also keeping in mind that you will need to adjust for either one of the colour temperatures.

Go to manual exposure mode and expose for the important part of the scene.