Cascade style can have apex or no apex or dead wood apex or no dead wood apex. There is no defined limits, or limits to where the apex occurs on the trunk. i see no problem with a small upright apex where your to branch is.
you will probably run into problems with different strength and vigor though. Higher areas of pine grow way faster than lower sections so that apex will grow and thicken while the cascade section will likely hardly grow at all. Adding a sacrifice shoot there will only aggravate the problem. This is not only light but also hormone and nutrient flow. You will need really good pruning and management skills to maintain this tree while it develops but you can always fall back on removing the cascade branch and reverting to informal upright if it all becomes too hard.
All the best with the project.
BTW I believe these are Scots pines as in Scotland rather than belonging to someone called Scott