Я сделал ещё несколько, сообщений довольно много, поэтому буду добавлять их по мере появления или если посчитаю, что они полезны.
<!--
<decoder name="unifi-udm-pro-se-fw-fields">
<parent>unifi-udm-pro-se</parent>
<regex type="pcre2">DESCR="(.*)"\sIN=(\S*)\sOUT=(\S*)\sMAC=((?:[A-Fa-f0-9]{2}[:-]){5}(?:[A-Fa-f0-9]{2}))

(?:[A-Fa-f0-9]{2}[:-]){5}(?:[A-Fa-f0-9]{2})):08:00\sSRC=(\S*)\sDST=(\S*)\sLEN=(\S*)\sTOS=(\S*)\sPREC=(\S*)\sTTL=(\S*)\sID=(\S*)\s(?

?:(DF)(?:\s)|))PROTO=(\S*)\sSPT=(\S*)\sDPT=(\S*)\s</regex>
<order>rule,interface_in,interface_out,source_mac, destination_mac,srcip,dstip,framelength,tos,prec,ttl,id,actionflags,protocol,srcport,dstport</order>
</decoder>
<decoder name="unifi-udm-pro-se">
<prematch type="pcre2">^.*(\[LAN.*\])\s</prematch>
</decoder>
-->
<!-- ubios-udapi-dhcp сообщения -->
<decoder name="unifi-udm-pro-dhcp">
<prematch type="pcre2">^.*(dnsmasq)</prematch>
</decoder>
<decoder name="unifi-udm-pro-se-dhcp-fields">
<parent>unifi-udm-pro-dhcp</parent>
<regex type="pcre2">(dnsmasq-dhcp)\[(\d{1,8})]:\s(\w+)\((.*)\)\s(\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3})\s((?:[A-Fa-f0-9]{2}[:-]){5}(?:[A-Fa-f0-9]{2}))\s(.*)</regex>
<order>process.name,process.pid,command,interface_in,port.local.ip,destination_mac,hostname</order>
</decoder>
<decoder name="unifi-udm-pro-se-dhcp-fields">
<parent>unifi-udm-pro-dhcp</parent>
<regex type="pcre2">(dnsmasq-dhcp)\[(\d{1,8})]:\s(\w+)\((.*)\)\s(\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3})\s((?:[A-Fa-f0-9]{2}[:-]){5}(?:[A-Fa-f0-9]{2}))</regex>
<order>process.name,process.pid,command,interface_in,port.local.ip,destination_mac</order>
</decoder>
<decoder name="unifi-udm-pro-se-dhcp-fields">
<parent>unifi-udm-pro-dhcp</parent>
<regex type="pcre2">(dnsmasq)\[(\d{1,8})]:\s*(\w+),\s(.*)\s(.*)</regex>
<order>process.name,process.pid,command,audit.command,file</order>
</decoder>
<decoder name="unifi-udm-pro-se-dhcp-fields">
<parent>unifi-udm-pro-dhcp</parent>
<regex type="pcre2">(dnsmasq-dhcp)\[(\d{1,8})]:\s(\w+)\((.*)\)\s((?:[A-Fa-f0-9]{2}[:-]){5}(?:[A-Fa-f0-9]{2}))</regex>
<order>process.name,process.pid,command,interface_in,source_mac</order>
</decoder>
<!-- ubios-udapi-server сообщения -->
<decoder name="unifi-udm-pro-services">
<prematch type="pcre2">^.*ubios-udapi-server\[</prematch>
</decoder>
<decoder name="unifi-udm-pro-se-services-fields">
<parent>unifi-udm-pro-services</parent>
<regex type="pcre2" offset="after_parent">(\d{1,7})]:\s\[(\w+)]\s(\w+-\w+-\w+):\s(.*"(\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3})")\s(\w+):\s(.*)$</regex>
<order>process.pid,process.args,process.name,lookup,remote.ip,result,status</order>
</decoder>
(\d{1,7})]:\s\[(\w+)]\s(\w+-\w+-\w+):\s(mdns data):\s(.*)
<decoder name="unifi-udm-pro-se-services-fields">
<parent>unifi-udm-pro-services</parent>
<regex type="pcre2" offset="after_parent">(\d{1,7})]:\s\[(\w+)]\s(\w+-\w+-\w+):\s(mdns data):\s(.*)</regex>
<order>process.pid,process.args,process.name,program,status</order>
</decoder>
<!-- DPI flow stats -->
<decoder name="unifi-udm-pro-dpi">
<prematch type="pcre2">^.*(dpi-flow-stats)\[</prematch>
</decoder>
<decoder name="unifi-udm-pro-se-services-fields">
<parent>unifi-udm-pro-dpi</parent>
<regex type="pcre2">.*(dpi-flow-stats)\[(\d{1,5})\]:\s(\w+-\w+-\w+)

.*"(\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3})")\s(\w+):\s(.*$)</regex>
<order>process.name,process.pid,process.command,lookup,remote.ip,result,status</order>
</decoder>
<decoder name="unifi-udm-pro-se-services-fields">
<parent>unifi-udm-pro-dpi</parent>
<regex type="pcre2">.*(dpi-flow-stats)\[(\d{1,5})\]:\s(\w+-\w+-\w+):\s(.*):\s(.*$)</regex>
<order>process.name,process.pid,process.command,program,status</order>
</decoder>
<!-- firewall сообщения -->
<decoder name="unifi-udm-pro-se">
<prematch type="pcre2">^.*(\[.*\])\s</prematch>
</decoder>
<decoder name="unifi-udm-pro-se-fw-fields">
<parent>unifi-udm-pro-se</parent>
<regex type="pcre2">DESCR="(.*)"\sIN=(\S*)\sOUT=(\S*)\sMAC=((?:[A-Fa-f0-9]{2}[:-]){5}(?:[A-Fa-f0-9]{2}))

(?:[A-Fa-f0-9]{2}[:-]){5}(?:[A-Fa-f0-9]{2})):08:00\s</regex>
<order>rule,interface_in,interface_out,source_mac,destination_mac</order>
</decoder>
<decoder name="unifi-udm-pro-se-fw-fields">
<parent>unifi-udm-pro-se</parent>
<regex type="pcre2">\sSRC=(\S*)\sDST=(\S*)\s</regex>
<order>srcip,dstip</order>
</decoder>
<decoder name="unifi-udm-pro-se-fw-fields">
<parent>unifi-udm-pro-se</parent>
<regex type="pcre2">\sSRC=(\S*)\sDST=(\S*)\sLEN=(\S*)\sTOS=(\S*)\sPREC=(\S*)\s</regex>
<order>port.local_ip,port.remote_ip,framelength,tos,prec</order>
</decoder>
<decoder name="unifi-udm-pro-se-fw-fields">
<parent>unifi-udm-pro-se</parent>
<regex type="pcre2">\sTTL=(\S*)\sID=(\S*)\s(?

?:(DF)(?:\s)|))PROTO=(\S*)\sSPT=(\S*)\sDPT=(\S*)\s</regex>
<order>ttl,id,actionflags,port.protocol,port.local_port,port.remote_port</order>
</decoder>
<decoder name="unifi-udm-pro-se-fw-fields">
<parent>unifi-udm-pro-se</parent>
<regex offset="after_parent">LEN=(\S*)\sMARK=(\S*)</regex>
<order>packetlength,mark</order>
</decoder>
<decoder name="unifi-udm-pro-se-fw-fields">
<parent>unifi-udm-pro-se</parent>
<regex type="pcre2" offset="after_parent">URGP=(\S+)\sMARK=(\S+)</regex>
<order>urgp,mark</order>
</decoder>
<decoder name="unifi-udm-pro-se-fw-fields">
<parent>unifi-udm-pro-se</parent>
<regex type="pcre2" offset="after_parent">SEQ=(\S+)\sACK=(\S+)\sWINDOW=(\S+)\s((ACK FIN)|(ACK PSH)|(ACK SYN)|(ACK)|(SYN)|(FIN))\sURGP=(\S+)</regex>
<order>seq,ack,window,flags</order>
</decoder>
<decoder name="unifi-udm-pro-se-fw-fields">
<parent>unifi-udm-pro-se</parent>
<regex type="pcre2" offset="after_parent">\sURGP=(\S+)\sUID=(\S+)\sGID=(\S+)\sMARK=(\S+)</regex>
<order>urgp,uid,gid,mark</order>
</decoder>