I’d certainly try taking the front rack off and putting faster tires on. Gatorskins or Hardshells 32mm for example.
Are you happy with your riding position? Your handlebars look to be a few inches above the saddle. Lowering them would give you a more aerodynamic position, but this is a matter of fit, comfort, and choice.
Lighter wheels without a dynamo would make a difference, but be a more expensive change, so maybe wait with that?
What kind of bags are you using to tour with, panniers or bikepacking bags? The latter are more aerodynamic thus faster but may or may not be suitable for your tours.
Keeping the weight of all your gear as low as possible makes a difference as well, of course.
Thanks. Judging by the responses so far, it sounds like trying lighter tires should be my first step. (I seem to be in a minority position on this, but I've had terrible luck with Gatorskins, however.)
I do like my current riding position on my AWOL, even though it's higher than on my road bike. Thanks for pointing that out, though; I'll play with it and see if I'm comfortable going a little lower.
I plan to keep a dynamo of some sort on this bike, in any case. So for me, it's not a choice between a dynamo and no dynamo. Rather, it's a choice between my current Shimano dynamo and a potentially more efficient SON dynamo.
I'll be using panniers, at least to start with, because I already own them for commuting purposes.