I don't know if you've considered the RusselK loudspeakers, but you say you have had Epos ES14s and Kans in the past, and I think the smaller RusselK Red50s are in many ways spiritual successors to those, in terms of sheer musical communication, but they also do timbre and beauty in a way the Kans never did, bass too. The larger, but still standmounted, Red100 is more of the same.
I have the floorstanding Red150s in a room slightly smaller than yours; they are just set into a bay window, with about 40-50cm space behind and to the side, and they work beautifully there. If you need to go closer to the wall, the standmounters will fare better, probably, and you don't lose all that much. They are not the prettiest, proportions like an old Linn Sara so quite square, and dealers often have them with a red front baffle which can be offputting, but in gloss black, or oak with a black front baffle, I think their looks definitely grow on you.