Hmm, you have slightly less than SL's recommendation of 25 sq m. My room is slightly larger (in length) but about the same width and I do wish I could get the speakers further apart, but I think the recommended 3ft to nearest reflecting surface is important, too.
I have used mine in a much larger room and they really do like to have space. I recently came across this comment from an EE, who I have a lot of respect for, who heard my LX521s at a local hifi get together a few years ago.
https://pinkfishmedia.net/forum/thr...inroads-in-to-hifi.211428/page-4#post-3302761
I also took them along to an ethusiasts show here in the UK a couple of years ago and was allocated a small first floor room with a very springy floor - much smaller than yours - and ended up not showing the speakers as the bass sounded really awful. Above transition the speakers sounded (and measured) fine, but the bass was full of large peaks and dips that I couldn't eq out and the bare floor boards resonated strongly. Very disappointing.
I don't use any bass traps or physical room correction other than a bookcase about 6ft behind the speakers so you might be able to use some form of absorption. I think there are a couple more LX521 owners on ASR so perhaps they can chime in with their experience regarding room size also.