How do you do it now? The odds of guessing another player's route between two points vs. trying to catch them at a destination - I know which side of that bet I'd take. Anecdote: I have never been interdicted by a player outside a destination system.
If it were up to me....
Passing through a system you'd
already visited would not require dropping out of frameshift and aligning on the next star. Instead, you'd have the option to play a mini-game (possibly inspired by
At the Core). Failure of the minigame would result in a forced exit from frameshift similar to losing an interdiction. Success would reduce fuel consumption and give faster real-world transit time. Opting out of the minigame would result in normal fuel consumption and an extended "frameshift" loading screen comparable to the current real-world time it takes to drop out of hyperspace, realign and jump.
Equipping a Wake Scanner would give a CMDR the ability to purchase Navigational data on all "open" players within [Module Class] x [Light Years]. The data would highlight the destination system as well as the size of the ship's FSD (but not commander ID or any detailed information about the target ship). Selecting a particular target ship/FSD signature would cost additional funds and reveal their plotted route. The target would receive an in-game email informing him of incoming attackers (similar to existing mission mechanics). The aggressor would attempt to get to one of the systems in the plotted route before the target (and before the destination system). If successful, the aggressor (who would need an interdictor equipped) would have the opportunity to affect a hyperspace interdiction. If the aggressor failed, they'd still be able to attempt a classic interdiction at the destination system if they could get there fast enough.
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The problem I have with increasing the time spent in real space flying to stations is that it increases the time from A to B without giving any additional gameplay. That's a big ask considering how infrequent piracy actually is. You could cut supercruise time by "x" and increase real-space flight time to station by that same "x" and I wouldn't complain, but I don't think it would create a large enough window of opportunity to matter r.e. PvP/Piracy.