Distance from wall for KEF Reference 1s

Every room is sonically different; different construction, walls, floors ceilings windows...try one of several available set up discs. My go to is from Stereophile decades ago. Maybe they still offer it

Your ears are the best judge. 

Cardas, among many others just give another perspective

Speaker Placement | Cardas Audio

Based the calculator, that distance is for a room around 8 feet wide.

Not a guide for a living space, as it encourages breathing room for the speakers, which can produce amazing results but as always-YMMV

I have my ESL's pushed way out into the room-about 7' in 26' long room.

Every room is different so you will have to spend some time trying different positions to see what your ears like.  What you "hear" is the only thing that matters.  I have KEF ref floorstanders in my TV room but that is for an Atmos setup so recommending something from that room would be apples & oranges to you.  

My two channel room might be helpful.  I had some really nice sound going but thought the imaging could be better.  listening to rock the vocals were getting tangled with the drums.  I looked around for advice to get the speakers from 90% to 100% to my ears.  This is what worked for me.  First understand that you want the speakers about 20% into the room off the front wall and somewhere between 7 and 9 feet apart.  Assuming that is achievable Focal recommends a very specific formula the create the optimum amount of space around the speakers.  

Here is the formula from Focal:  If A is the distance from the centre of the woofer to the nearest floor or wall, B is the distance to the next closest floor or wall, and C is the greatest distance (A < B < C), the equation B2 = AC defines the ideal loudspeaker position.  Example:  If the centre of the woofer is 20" (50cm) away from the rear wall (A) and 24" (60cm) above the floor (B), then the side wall will be ideally 28" (72cm) away [C = B2 ⁄ A = 28" (72cm)]  Note that measurement A will most likely be the distance from the woofer to the floor.

My room is 13'w 16'L 8' ceilings, the front wall where the speakers is the 13' length.  When all was said and done the speakers are 33" from the side walls and 43" from the front wall measured to the tweeter in front.  This optimized the soundstage and I liked to tonal balance.  I don't think it matters that the recommendation is from Focal and you're running KEFs.  Sound is physics and math is math.  Good luck and cheers.  

In my original post I should have mentioned that I've used the Reference 1s for over 5 years.  An interview with Jack Oclee-Brown I saw on YouTube lead me to reduce the separation of the speakers to create an equilateral triangle and to remove toe-in.  The sound improved considerably.  The room is 14' X19' X 8' with books and posters.

In the living room I had LS50 W2s against the wall rationalizing that the pair of KC62 subs handled LF.  But when I pulled them away from the wall the sound improved dramatically, with a nice sense of soundstage depth without compression.

Refer to the manual for starters- it should clearly indicate distance from wall options vs, recommended port options.