A friend of mine have 2018 CF and his fitter drilled new holes in the armrests to get more narrow. Looks real nice, it almost looks like you are supposed to drill your own holes to get that narrow. His fitter is very well known, espacially here in sweden and he works for a world tour team that last year rode cervelo...
I own a 2018 CF to and needed to get longer so i just removed the original stem and spacer and replaced them with a 100mm stem and a couple of ordinary spacers, doesnt look to good but funcionality before looks...