For those interested, until you find an fwbuilder alternative, a kludgy
but effective way to implement the workaround for the
fwbuilder-generated scripts' deprecated "-m state --state" usage is to
use the following (on linux, with pkg "ed" installed) as a custom
printf '%s\n' 'g/-m state --state/s//-m conntrack --ctstate/g' w | ed -s
/full/path/to/my_script_name.fw && /full/path/to/my_script_name.fw
using this, installs and exec are both ok.