It should not matter since they have DSP to adjust for placement.
Don't know about LS 60 vs KEF Reference but FWIW always found speakers placed only a few feet from the walls behind them tend to sound flat imaging wise (probably with enhanced bass) whereas a monitor speaker usually had greater clarity and 'depth' of image when placed out about 4 to 5 feet from the wall but with some loss of bass (unless you found a bass node to set them in). That's the reason many folks use subs with small speakers. Try placing the 60's in the same place you have the Reference's and see if it sounds better (to your tastes) than so close to the wall. Its a trade off that I would vote for even if I had to get subs to flesh out the bass.
I have no problem setting the LS60s where the Reference 1s are now. The Reference 1s are augmented below 80 Hz by a pair of Velodyne HGS 15s with acoustic room correction. I assume there will be no problem using the subs with the LS60, but might bypass the crossover of the SMS-1 bass manager given the KEF Contact app has bass management. Im not sure how Contact and the SMS-1 will play together.
Haven't heard e LS60,. just read and seen reviews. Kal Rubinson's review for Stereophile was the most convincing. At 87, I'm aiming to simplify with a setup that's easy to use but sounds good. The KEF Reference1s, driven by the Ayre KX-5 Twenty preamp and VX-5 Twenty amp, sourced by Ayre QX-5 Twenty Roon-ready DAC and DX-5 DSD disc player is a tough act to follow. I'll be keeping the Ayre disc player and phono amp. it's most likely I'll buy a LS60 next month before I sell existing gear.
@dbphd Bass management and crossovers are two different beasts, and one is definitely not a substitute for the other. The only exception to this is that most AVRs bass management does crossover as well as level and EQ.
IIRC the Velodyne SMS-1 does both low-pass crossover and bass management. The first is a simple setting of frequency and slope, the second entails acoustic measurement of sound generated in the room. You can let the SMS-1 seek a solution based on the measurements as it adjusts its way along the spectrum or you can tweak the bands if you’re so inclined, and there are lots of things to tweak. Full range analog goes from the Ayre KX-5 Twenty preamp to the SMS-1. I’m assuming analog will go from the pair of LS60s to the SMS-1, but the KEF Contact app may low-pass it. I may be wrong. Of course the SMS-1 sends room corrected analog to the pair of HGS-15s.