So is it the scale length of your T-Bird that you find uncomfortable or the overall size of the bass?
I play 99% of the time sitting down, I am not in a band. It's just not a good sitting down Bass IMO if you have it on one leg the 1st fret is a mile away and if you have it on the other leg than the higher frets are too far away. Its just not a comfortable sit down Bass like a Fender is.