I propose a setting under options, that loads a pre-configured config-file that makes the whole game(graphic,sound,controls, etc...) match a freshly installed dos version as closely as technically possible.
For example: In GZDoom, you need to fiddle with many sub-menus(and a few console commands) that are hidden under some rather technical terms, in order to get close to choclatedoom in look and feel.
I think making a simple easy-to-find option that does all this at once in Raze (and warns the user it will wipe the current config-file), will be much appreciated.

Each game will obviously have its own unigue preset, for duke3d it could scale the output to look like an 800*600 resolution(black bars at the sides on widescreen), a setting that emulates the old 256-color look,"nearest"-texture filtering, etc... choose a soundfont to something that people had back then(the 1mgm awe32-rom-soundfont or the roland sc-55, or just opl).
If you make such an option very easy to find, then I don't think people will complain much about the default settings.