Maybe it is better if you make post you must gathegory/tag it and thous tags are already given:
(something like this)
- Spoilers
- Opinion / freely written or when you finish episode or drama/movie or write review and tag/link drama title /
- Drama trivia / images,ost,/
- (Drama) News / about actors, coming dramas, rateings aso./
- Slice of life / all about yourself and your everydaylife /
- Other / all what doesnt belong under previous tags /
And you can choose on your friends profile list what kind posts you want or not want see from him.
If he/she posts spoilers tagged and you dont like spoilers then you just block from him/her posts with that tag a.s.o.
And you can do this from your profile list to be by default, not personalised but in general too.
If you dont want get on feed posts with that tag at all.
And i think that some feedback to posting person is nessesary, of course not by names but by numbers - how many his/her friends block some tag.
It is kinda sad of person is posting and posting even not knowing that majority of his/her friends dont read thous posts.
Seeing numbers he/she can decide itself - keep up posting under this tag or not.