Good question

One that I asked myself when honing on the Nakayama and off the Shapton 30k

I tried it both ways for quite some time I went with just leather after the honing on those two for a couple of years, now I am back to both Linen and Leather again..
Didn't really ever notice a difference, but I feel way more comfortable using the linen after honing, especially on customer's razor, Linen will find any issues..