Na man, you go to 'Fretted Instruments' when you set up a composition, there you can select:

Standard guitar TAB
Dropped D guitar TAB
D standard guitar TAB (But doesn't seem D to me??
7 string guitar TAB

and a range of Bass staffs in TAB including 6 string bass.

I certainly compose in tab, fuck proper music takes too long, and anyway, I feel I can get more creative in TAB.