Any suggested solutions or workarounds for this?
I tried using iptables-translate to help, which doesn't appear to be available on OpenWRT, but that didn't help. I looked at Firewall4 / NFtables Tips and Tricks - #59 by noblem which led me to try this, which worked:
#iptables -I input_rule -p tcp --dport 80 -j ACCEPT -m comment --comment "ACME" || return 1
#ip6tables -I input_rule -p tcp --dport 80 -j ACCEPT -m comment --comment "ACME" || return 1
nft insert rule inet fw4 input tcp dport 80 counter accept comment \"ACME\" || return 1
and also for the later section:
#iptables -D input_rule -p tcp --dport 80 -j ACCEPT -m comment --comment "ACME" 2> /dev/null
#ip6tables -D input_rule -p tcp --dport 80 -j ACCEPT -m comment --comment "ACME" 2> /dev/null
nft insert rule inet fw4 input tcp dport 80 counter accept comment \"ACME\" 2> /dev/null