Very nice !! That must be tough deciding out how far forward or back you place the platform relative to the dovetail?
... it's hard to tell in the picture, but is the front of the platform covering the extractor pin hole on the top of the slide? If so, seems like you'd want the platform to shift slightly rear-ward so sight platform removal isn't necessary whenever you need to remove/service the extractor? So enough clearance to access the hole/pin with a punch.
That is determined by where the holes are for mounting the scope the plate and the dovetail set screws. You would need to remove the scope to service the extractor.