The following may not be relevant if you only play in Private Groups and/or Solo but it's interesting nonetheless...
I noticed this thread in the E:D forum:
https://forums.frontier.co.uk/showthread.php/367388-Lead-Designers-advice-on-dealing-with-griefing-(part-2)
The upshot is that, where we might have thought that the in-game "Block" function only blocked a player's communications in the chat window, it does actually go some way toward blocking the player being instanced with you.
As I said, this may only be of use to you if you play in Open mode, and as this is the Mobius PG forum, it may be hypothetical. Nevertheless, I conducted my own experiments in Open mode...
...and it does work! Over the last couple of weeks I went to some Community Goal locations and flew about in a cheap Imperial Courier. Yes, indeedy, plenty of griefing and ganking going on - laying mines in stations, shieldless suicide ganks, etc, etc (basically just a bunch of nob-heads with neon hair in their avatars). In the end I was ganked quite a few times (I'm not complaining, this was part of the experiment). Each time I was ganked I put that player on my Block list. Sure enough, I no longer get instanced with said gankers.
So, if you do play in Open mode, it might be worth filling your block list as per the instructions in the linked forum post.
Here's an idea - all Mobius players en masse play in Open mode and populate their block list with the same gankers. Then just start playing in Open mode - the result being that there are no instances with other players for the gankers to appear in, so they just instance with each other.