DSB Logout Manager timed warning?

When using the timer in the logout manager for shutdowns, is there any way to add a warning - say 5 minutes beforehand before the timed shutdown occurs so that the user can change things beforehand if they are still active?

I’m running NomadBSD in a solar-powered fashion on one project driven by the typical power bank. I use the shutdown timer to save the battery should I forget and walk away.

However, unless I keep tabs on it by visiting the dsblogoutmgr icon in the tint bar when I’m active, I could be in the middle of something and - bam, shutdown if I forget to check.

I’m looking into some scripting like cron, at, and the like to throw up a dialog-box to do the timed-shutdown from the cli with a pre-warning, but would love to see a pre-warn from dsblogoutmgr itself. I don’t know if it’s possible though.