I'm running a 9s Miche cassette on my 8s setup with one cog taken out, the 23t. I'm thinking of taking out one of the smaller cogs and putting the 23 back in. Which would you guys recommend? I can't take out the 12 without switching my lockring, or am I mistaken?

Cogs: 12, 13, 14, 15, 16, 17, 19, 21, 23