Have you played live with the T? What approach do you use?
Yes, I'm a full-time touring musician and recording artist, and the Tempest is one of my main instruments, both on the road and in the studio. I work in all capacities as a solo artist, session player, sound designer, engineer, and producer. Onstage, I'm often physically playing the Tempest and improvising sequences on-the-fly; but I also do EDM style gigs with prepared beats and sequences, so I do understand your plight. When I'm travelling with minimal gear and I need to bridge the silence between tracks, loading new projects on the Tempest for instance, I use one of three tricks depending on what kit I have with me:
1) I manually trigger a sample on my SP-404SX while I change projects on the Tempest...
2) I capture a live loop on either the Octatrack or one of my Boomerang III looper pedals...
3) I ride the "infinite" feedback of a tape echo...
Of course the material will determine which of those techniques is going to work best.
Otherwise, when I'm travelling with
a lot of boxes, I use the SND ACME-4, which sends four parallel MIDI clock signals; that way I can start, stop, subdivide, and offset the clock source for each device independently and always be in sync.
Honestly, when it comes to travelling light, it doesn't really get anymore concise and comprehensive than a Tempest/Octatrack combo. If you were to ditch the Octatrack, but still hope to create transitions, you're only going to have to bring something else in its stead and suffer yet more limitations. You'd be better off loading your Tempest beats into the Octatrack and just bringing that, as suggested above. That's my two cents anyway...
Cheers!
*Edit: I've also been known to trigger an arp or sequence on a keyboard, or play a riff with my left hand while I change projects on the Tempest with my right. So if you gig with keys, that's also an option.