msdosfs_iconv issues

[blubee blubeeme]

according to man msdosfs

I can run a command like this:
mount_msdosfs -L en_US.UTF-8 /dev/da0s1 $HOME/usb

this always returns operation not permitted.

looking into that a bit further it seems that I need to load a
msdosfs_iconv.ko and that needs to be root, using
/etc/rc.conf
or
/boot/loader.conf

the module is loaded at boot time but I still get operation not permitted.

if I remove the locale option from mount_msdosfs the file loads but of
course, I cannot read any of my documents.

This seems a bit odd but I understand that constantly loading msdosfs_iconv
can DDoS the system fine.

How can I mount my drives with locale or at least proper utf-8 encoding?