A stand is at the 0.1% difference level.
Empirical evidence to support that statement? Current system or systems in which you have experimented with stands? That philosophy is a vestige of yesteryear when everyone had their gear sitting on the carpet.
I found this old article from 1992 documenting the speaker stand "debate." An interesting read. I do wish there was a little more data to substantiate the claims of current isolation technologies.. This is a little surprising since several companies have engineers involved.
Stands can make a significant difference in my experience. My non-audiophile wife could hear the difference in blinded tests. It is readily discernible and obvious. The degree of change can vary based on equipment type and design elements and degree of system resolution.
Start with your speakers and work backwards. I am a Sistrum fan and they offer a trial period. Stillpoints and Equarack are also good products that I have used. Try them and see for yourself. Don't be swayed by vague, prosaic statements by "Elizabeth" or me or anyone else.