Speaker cable lifters.

I’d tried ceramic, wood, laser printed, popsicle sticks, etc. On tile or wood flooring, raising my cables mainly keep dust bunnies from clinging and very little else. On carpeted floor, I do hear a difference especially during dry winters. I found them most effective with non-shielded cables, speaker and interconnect cables alike. If one takes the extra effort to use cable risers, he/she will mostly make the extra effort to dress their cables properly. Such as separating power, interconnects, and speaker cables from each other. Usually an inch or so will do. Should cables touch,try one’s best to cross signal and power cables at reasonable angle. More perpendicular the better. I humbly believe cable dressing pays the biggest dividend. 

Finally, I came across and currently using a few Rebar Chairs in parts of my cable web. Cheap and effective. Many styles and heights to choose. One with perfect slot to slip in my Analysis Plus speaker cable yet able to hold a two inch diameter power cable with slight modification.

Hope you find this useful.
 

There is a option where as good as Zero Cost can be outlay to experience a propped or suspended Cable.

Usually the material used to contact the Cable is a organic origin instead of a synthetic substance, but who really knows.

I suspend my Speaker Cables with a Cotton Thread.

For Cables with a substantial girth like the ones being referred to, maybe a heavy duty Cotton Thread will be the required type if suspension is to be considered.

Looking at your system, there are plenty of attractive pedestals designs that would compliment it, my approach to all supporting equipment for Audio Ancillaries is very cost effective, robust and basic avoiding anything Heath Robinson. 

I built my own from 1x4 lumber. I drilled a 3" hole spaced every 12" then cut through the holes and you have a 3" x 1.5" hole to lay your cable in. I nailed a 1" x @' on the bottom of each for support and stained them all. I took about an hour to make about ten of them. The cost was ]probably $10 in parts.

' I really would like to call up a professional to come to look at my room and see what I really need for wall and ceiling diffusers / dampers'

A mic/room EQ program will show what going on. Just a guess, but diffusion is the issue to manage?

Controlling the room over tweaky addons would be seem to be the more important thing to address.

@tablejockey I agree, that getting the room set up to be a very good interface for the produced sound energy is a high importance.

Looking at the OP's set up, there is the possibility such a practice of getting the room set up to interface with the Speaker is addressed.  

As energy is always transferred, it is best to discover the methods that can be adopted to transform the unwanted energies into a form that has the least least impact on the quality of the Sonic being produced.

The interest in audio equipment will nearly always lead to investigations about how to eek the betterment, even the smallest of change, if seen to be resulting in a betterment, can end up being sought by certain individuals.

When I suspended my Speaker Cables with a Cotton Thread, they were no longer in contact with anything but the Terminations and Cotton Material.

Did suspending the Cables make a difference? It is not certain, but there are Cables in use that are in free space, and when I tidied up the Systems Cable Loom,  ensuring that there was a minimum of crossing over cables such a Power, Interconnect and Speaker, the improvement in the sonic produced was very noticeable.

Again something that can be achieved for next to nothing in monies outlaid, and highly recommended to take the time to put into practice.