I’m pretty sure most folks also set their Audio Tracks to Musical Timebase for most work. For tracking stuff like vocals or a band Musical Timebase would typically be most useful. Film folks, maybe not so much.
I wonder if you might be conflating Musical Timebase and Musical Mode.
Right now the Preference sets the default Timebase for all Track types. I suppose if you wanted to have different defaults for different Track types it would end up being a bunch of settings.
I’m not at Cubase, so can’t be specific but you could set the Preference to whatever you mostly need and then use a Macro and/or Track Preset to add the other ‘flavor’ when needed.