Another idea I had (which can be ignored, questioned or criticized in detail fairly rather than just attacked with accusations) (no, its true. no joke) is to have a timer where without enough variety of keyboard/ mouse input your capsule begins going into something we can call “emergency cryogenic status” (ECS). What that would mean is that your capsule begins an automatic process of putting you in a cryogenic sleep (seeking to save your AFK life) and your ship shuts down. After a fair warning (perhaps two minutes of klaxons going off) your name is dropped from local and your ship would be rendered immobile as well us immune to combat probing (as with wrecks). All your mods shut down. How all that goes depends on where you put your ship before going AFK. You stay that way until…
You come back to your keyboard/mouse and offer input. The ECS process is cancelled and a reversal process begins. Your name is back in local right away (but marked or fading in and out to indicate you are only half there) but for a time, perhaps five minutes, your ship is starting back up, so your modules don’t work and you still cannot be combat probed. After the time has elapsed your ship is back on line and everything goes as normal. Hope you had fun studying the ship tree or the market while you waited!
About the only way I see someone dying for this is that they went AFK in a really dumb place (their own fault), or someone has a gadzillion bookmarks and a very, very fast subwarp ship and a fleet to warp to that fast ship when it finally gets near. Those plus a REALLY good grasp of d scan AND enough luck to win the lottery. But same moral of the story; play the game or log off.
Edit: just for funsies I suppose d scan could work when you come back so you get a clue how close your frenemies got to you while you were away. Plus its fair in a contrived way cause they have been d scanning you the whole time.