Differ Solo and Self Found

What makes searching items more fun is that searching it with friends, without considering economy, just playing the raw game.

That is why I think self found should differ from solo. The engine should be robust enough to handle drops that self found players can still play in groups.
I do not like the idea for chasing items in solo without giving a choice. Self Found should be classified as "All items should be found by player.", while Solo should mean "Cannot group play etc.".
A solo should still be able to trade.

Solo Self Found should also still exist, which will not have any change.