The best thing to do in a terrible room is a near field system if the person will go with it.Just a remark coming from my experience...
I already have a small room 13 feet almost square...
Near listening help in a bad room in the sense that it "seems" a little less worst and it is in some measure...The direct sound coming from the speakers help.... Thats all....
My acoustical experiment worked improving my near listening (3 feet) also...
Then EVEN in near listening a room must be treated and under control acoustically... It is a myth that with near listening you are free to let your room untouched...In a non treated room, even in near listening the "timbre" experience will not be so natural and the imaging not so good....
It is my experience....
By the way i never pretended to have more experience than you for example in using an equalizer... I dont doubt your expertise with that and will ask you help when i will need to...
But i have also my experience and some unusual devices or materials did unexpected things for me...I dont want to be trusted on words but i dont want to be mocked either....Thats all....