Using a default domain name in Wine would be beneficial for certain Netapi functions. While it's no big deal to add a config option for that, there is the Windows registry value DefaultDomainName in HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon which could be used for exactly that purpose.
Is it better to - use a Wine config key, - use the above MS key, - or use both, the Wine key overriding the MS one if set?
Martin