You don't seem to have understood what I typed. You gain absolutely nothing by logging into 1.6. It just means you can't land on planets, and since the engineers are all on planets you can't access them. That is all. It doesn't make the game any more or less playable because the other players and NPCs you encounter in space still have their own engineering mods. You just miss out on an aspect of the game that you could otherwise gain at least some benefit from. The fact that you would still think asking "Can I turn it off?" is still a valid question when you've been told that doing so would not give you any benefit at all is why it's a passive-aggressive complaint. It's a form of complaining without actually complaining directly because instead you're saying you want to "not play Engineers" while still playing the game, when you could just as easily ignore that aspect of gameplay entirely. The other issues you mentioned, such as NPC interdictions, etc., are part of 1.6 gameplay. They have nothing to do with whether you choose to mod your ship and will cause you just as much difficulty whether you log in 1.6 or 2.1.
The OP states he he wants to get rid of the 'snowglobe' of materials being dropped on the scanner, something that would be stopped by being in 1.6.