the fact that you can travel to another system in SC and it doesn't instance is such a major failure from Day 1.
Why, if it's an action that you dont want to occur, do you allow it to happen at all? Fdev could easily implement a "navigation lock failure, emergency dropping Super Cruise" message to appear when you reach 2/3 of the way to the next system (or 1ly whichever comes first) and drop the player into normal space. From here, the player wont have the ability to enter SC, only high jump or fly around in normal space. Now being in normal space, traveling to another system would essentially be impossible. Win, and forcing the player to high jump means they can't circumvent permits or experience the "non-instancing" issue. Win.
what the hell Fdev. It's a solution that doesn't even really break immersion. Why was this not done from day 1?. Instead we have something that's incomplete that gives a poor user experience.
While I agree that not being able to SC to other systems is a failing, I don't think your suggestion would do anything to improve the user experience. Replacing something unfinished with an equally disappointing and more arbitrary barrier is needless.