It would appear that it's already "solved", from Frontier's perspective - they have chosen option 1: "Accepting telepresence".
.... which has the advantage of not, in my opinion, breaking the whole game by introducing fast travel (as, when the telepresence session ends, the player is placed back in their own ship where they were before they signed on as crew).
However I hope that Frontier at some point will switch from telepresence to NPC. As I mentioned earlier it can be really interesting gameplay mechanics, to have few NPC as your employees, of course they faces are created by you. You can train them (like SLF pilots) and use them for SLF pilots. You can also put them on the Crew NPC Market. Thanks to that anyone can "hire" them from any space station, because your NPC are free to travel and their are not tied to specific stations, thanks to that we can assume that they are in desired stations all the time. Of course everything earned by your employee belongs to you. You need only to give him few percentages of it!
It will also solve the problem with exploration multicrew, because your friend can take on board your NPC and also few other npc (you ale may have many NPC) and those NPC works as "remote link to multicrew", because when you participate in multicrew you are not playing as you but rather as you employee. It is a little bit more complicated than telepresence but it's open concept of "shareable" crew NPC, training them, using them for multicrew matchmaking and for multicrew with friends.
