As a general rule of thumb, the default values will adhere as close to Vanilla HDest as possible.
Presets are now split into three main areas: Full Presets, Non-Helmet Presets, and Helmet Presets.
Full Presets will update both normal and helmet settings, and are used for both static HUDs as well as Helmet HUDs.
Non-Helmet Presets will only update the normal settings, regardless of how they're used in the Full Preset.
Helmet Presets will only update the helmet-specific settings, regardless of how they're used in the Full Preset.
My own personal Preset has been added as a slightly tweaked UDV Preset (at least for now).
CVAR, MENUDEF, and KEYCONF lumps have been formatted as best as I can care to do so for now, at least to try and help my future self when sifting through these now massive files.
The ability to reset specifically non-helmet or helmet-specific settings has been added.