I've tried to cross compile an image but I end up with this build
failure:
> $ zcat
> /var/log/guix/drvs/fl/nrxka21fgd5hpbchzp3fyv01xyrs2v-linux-modules.drv.gz
> Backtrace: 5 (primitive-load
> "/gnu/store/lm7mjsdx6p16pbavv80hpf561df?") In ice-9/eval.scm:
>     619:8  4 (_ #f)
>    626:19  3 (_ #<directory (guile-user) 7ffff5fdbc80>)
>    293:34  2 (_ #(#<directory (guile-user) 7ffff5fdbc80> #<procedu?>))
> In srfi/srfi-1.scm:
>    586:17  1 (map1 ("ahci" "usb-storage" "uas" "usbhid" "hid-gene?"
> ?)) In gnu/build/linux-modules.scm:
>     257:5  0 (_)
> 
> gnu/build/linux-modules.scm:257:5: kernel module not found "ahci"
> "/gnu/store/is9dg680cwlzhj6k6j0vxz86zwkqvx5m-linux-libre-6.0.8/lib/modules"

Though I don't know if it is related or not to your issue.

Denis.