It would be good to have multiple preferences "profiles", which would store all your preferences settings under a profile name. You could then swap between them.
Sometimes use different ASIO (or even WDM) devices, MIDI devices & Control Surface settings for tracking certain projects compared to others, and a fairly standard setup for mixing.
Currently I have to resort to copying various backups of AUD.INI,TTSSEQ.INI & Cakewalk.ini around - and even then this invariably leaves things out that need tweaking afterwards.
Being able to switch quickly between these would be great.