I fail to see how this would practically work....
You have a mission trying to deliver stuff to HardToReachStation in GankFest101, no indication about any dangerous CMDRs in the system, so you jump...
So now any potential dangerous player could do any of the following
- Mode swap. They are in the systm, but in Private/Solo mode, and now they want to go looking for others, so they relogg into Open.
- They where logged out, and just decide to login, and they where already in the system, you jumped to.
- They where in a neighbouring system, and decided just decided to travel to your system
And we have not even started to consider how instancing work in this game.
A potential dangerous players is sitting at a station, conflict zone, settlement, mining location, so that is all different instances than what the super cruise instance is. Should that player be shown to be present in the system? Because you are unlikely to encounter this player..
We have then not even started to consider block list, and how that affects instancing. Because if you jump into a system, and have blocked the player that is present, you will not instance with that player. So if that player is present and shown that a potential dangerous player are in the system, then you would get a false warning.
So I do not see how this system ever can work as you want it to, it will be filled with some many if's and but's that makes it more or less worthless. and what would the most likely course action be on your part, if a potential dangerous players is a in a system you want(/need) to travel to? Like you have a cargo delivery mission, want to visit and engineer, etc, etc, wait for the other player to leave? Try to that approach if you want to attend a community goal in Open.... So the obvious action you will do is, is what you already can do to avoid potential dangerous players, play in Solo or Group mode.
Showing players differently on the radar, would that really change anything? as any player is a potential threat, regardless if they are lilac or not normal colour.