Show disconnected host names in nlbwmon / Netlink Bandwidth Monitor

I have nlbwmon set up and working well. However, I noticed that when a client goes of the LAN (such as a phone leaving the premises), nlbwmon no longer shows a useful host name.

In most cases, I can find this out by looking at my Unifi Wifi controller, though this wouldn't work for wired clients that are disconnected.

It looks like the app calls network.rrdns to get the host names. and that only works with clients that have active leases:

(Aside, wow the ubus command at the CLI is neat!)

Anyone have suggestions on ways to improve this?