I think what works against James is also that DT's instrumental passages are both longer, and complex. There's only so much you can do on stage without singing, especially if the instrumental sections are not singalong-ish like, for example, Maiden's (Phantom of the Opera has a long solo section but a singer could use most of it to keep the crowd going), and if you don't play anything.... so James either plays the tamburine like he did in the FII days, just to have an excuse to remain on stage, or at a certain point he has to walk away.
Speaking of long solo sections, did Jeff remain on stage during God of the Sun and Labyrinth? and if he did, what did he do?