iptables-translate -A INPUT -m tcpmss --mss 42
nft add rule ip filter INPUT tcp option maxseg size 42 counter

iptables-translate -A INPUT -m tcpmss ! --mss 42
nft add rule ip filter INPUT tcp option maxseg size != 42 counter

iptables-translate -A INPUT -m tcpmss --mss 42:1024
nft add rule ip filter INPUT tcp option maxseg size 42-1024 counter

iptables-translate -A INPUT -m tcpmss ! --mss 1461:65535
nft add rule ip filter INPUT tcp option maxseg size != 1461-65535 counter