Sorry Anjaq. I didn't mean to make you feel frustrated.
I am not a surgeon and I was judging based on a few cropped photos, so take what I wrote with a grain of salt and consult with some FFS surgeons about this.
Most FFS surgeons operate the upper segment of the nose from above, using the same incision that is used to access the frontal bone, as this upper segment of the nose is not reachable through the nostrils with the usual rhinoplasty techniques. So in case you now get the bump removed off the bridge and the tip of your nose done in a way that matches the future forehead reset (which would require some kind of clairvoyance or futurology talents from the rhinoplasty surgeon but is not impossible), then you might not need to redo the rhinoplasty work when you undergo the forehead surgery. It might be possible for the forehead surgeon to reduce the top of the nose from above in a way that matches the rhinoplasty of bridge and tip that was previously done from below. If the rails of the transcontinental railroad matched in one spot coming in opposite ways from the west and east coasts, approaching your nose from above and below in a seamless way shouldn't be impossible, as long as all the parts are calculated to fit into the right proportion. You won't have all the chances on your side, though.
The best thing to do, I think, is consulting with the FFS surgeon of your preference.