In the ZQuest Options window (accessible via EtC->Options), in the Settings tab, the ? button to the right of the "Uncompressed Auto Saves" checkbox is permanently greyed out.

ZQuest Classic Editor, Version: 2.55
Tag: 2.55.0 Nightly (Alpha 118/119)
Build Date: 21st January, 2024 at @ 21:15:19 EST