OK, it's been up about 11 hours now, and I'm seeing:
ubnt@ubnt:~$ ls -l /var/log total 2356 drwxr-xr-x 2 root root 40 Jul 31 06:25 apt -rw-r----- 1 root adm 214 Jul 31 17:06 auth.log -rw-r--r-- 1 root root 63 Jul 31 17:06 dhcp6c.log -rw-r--r-- 1 root root 37 Aug 1 03:57 dhcpd.status -rw-r--r-- 1 root adm 6758 Jul 31 06:25 dmesg -rw-r--r-- 1 dnsmasq root 2038 Aug 1 03:49 dnsmasq.log drwxr-xr-x 2 root root 40 Jul 31 06:25 fsck -rw-r--r-- 1 root root 292292 Aug 1 03:59 lastlog drwxr-x--- 2 www-data www-data 60 Jul 31 06:29 lighttpd -rw-r----- 1 root adm 0 Jul 31 19:17 messages -rw-r----- 1 root adm 2367344 Aug 1 03:59 messages.1 drwxr-xr-x 2 root root 40 Jul 31 06:25 mgetty drwxr-xr-x 2 ntp ntp 40 Jul 31 06:25 ntpstats drwxr-xr-x 2 proxy adm 40 Jul 31 06:25 squid drwxr-xr-x 2 proxy proxy 40 Jul 31 06:25 squid3 -rw-r--r-- 1 root root 77 Jul 31 17:06 ubnt-daemon.log -rw-r--r-- 1 root root 204 Jul 31 17:54 upnp.leases drwxr-xr-x 2 root root 40 Jul 31 06:25 user drwxrwxr-x 2 root vyattacf 120 Jul 31 06:25 vyatta -rw-rw-r-- 1 root utmp 384 Aug 1 03:59 wtmp -rw-r--r-- 1 root root 3456 Jul 31 17:10 wtmp.1
"show log tail" shows nothing, "tail -f /var/log/messages.1" shows logs in real-time.
You can see my current config.boot here: https://gist.github.com/sTywin/92e1ec2685a3263256dd0bfcf77e526a
