to summarise some of the info provided in the comments.
am i right to say the below:
Le encantan los documentales de historia, que/lo que/lo cual (yo) encuentro aburrido = I find [the fact] that she loves history documentaries boring.
Le encantan los documentales de historia, que/los que/los cuales (yo) encuentro aburridoS (agreement of the adjective is necessary here) = I find history documentaries boring.
meaning to say, que = lo que = lo cual are interchangeable and replaceable with no change in meaning. same for que = los que = los cuales ?
