Price is steep as Rick mentioned and they will not give you a lot more (if any) significant improvement in terms of sound quality (and placement characteristics) over the KEFs in the first place.
Where are your speakers located now I wonder?
I previously missed the pictures you shared on the first page and have some additional thoughts now I've atually seen your space next to the drawn floorplan.
I'd meditate on listening needs and optimising placement accordingly.
My assumption/approach is that this will lead to re-orienting the speakers to a different location: Firing towards your listening spot (where you listen to music most intently).
You could view that intent-listening-space as the base 'square' and optimise setup and subsequently space for the square that your listening square resembled the most in the linked Cardas guide. As you might be missing a (couple of) walls compared to the Cardas squares a bit of experimentation is needed to dial it in.
Other parts of the living space can be viewed as different 'zones' that either have suboptimal sound (which is true in my case, I listen to reflected sound in the kitchen, but that's totally fine for me whilst cooking). Or if intent listening is also desirable in the 'zones', set up separate systems or secondary speaker pairs (as most amps can run A/B speaker pairs) in other zones..
For reference (more to share that others have to go through certain steps that to reflect on your situation); My floorplan can be viewed as three rectangles oriented like a U with a wide horizontal. I sit in the horizontal most often so the sound dissipates/reflects needlessly into the vertical parts of the U.
Within my 'imaginary' listening square I started setup by adhering to Cardas' guide:
https://www.cardas.com/system-setup
Additionally, I've had to:
- Toe the speakers out for better soundstage.
- Realise that moving the speakers away from the wall 'like it should be' actually deteriorates the soundstage.
- Put up more art (canvas) with acoustic fabric on the back of the frame behind me. I've experimented with creating airgaps behind the frames, but that made no difference.
- Accept suboptimal sound in the kitchen (The right vertical part of the U).
- Set up a secondary system in the gaming/dj corner (The left vertical part of the U) and move a closed back cabinet that acted as a space divider away (dj setup in the same location now, but a fabric couch behind that is now the actual space divider).
- Resonating objects: Fill an aluminum doorframe with foam and replace a big metal industrial lampshade for a bamboo one.
I thought i was going to need carpets and heavier drapes but this was not the case at all.
All of it is in essence is playing with resonances and reflections.
