I prefer to pull configuration together in one place. I’ll usually use RecordWildCards for the actual settings record construction. I want to know statically that it’s all there.

data App = App
    { appSettings    :: !AppSettings
    , appStatic      :: !Static -- ^ Settings for static file serving.
    , appConnPool    :: !ConnectionPool -- ^ Database connection pool.
    , appHttpManager :: !Manager
    , appLogger      :: !Logger
    , appPostmark    :: !PostmarkSettings
    }

makeFoundation :: AppSettings -> IO App
makeFoundation appSettings = do
    appHttpManager <- newManager
    appLogger <- newStdoutLoggerSet defaultBufSize >>= makeYesodLogger
    appStatic <-
        (if appMutableStatic appSettings then staticDevel else static)
        (appStaticDir appSettings)
    let appPostmark = postmarkSettings (appPostmarkToken appSettings)
    let mkFoundation appConnPool = App {..}
    {... etc ...}

You can be cleverer than PartialOptions/Options and turn that into a type argument but it’s not worth it.