I love all of my TB products but have really found useful the strap-mounted version of the Guardian DF Light (don't know how to hot link to product page - sorry!).
I have one light attached to the closure strap on my hemp Swift. Hanging most of the time as shown, it serves as a safety light. When flipped over inside it's really useful to find contents lost in the depths of the bag.
The Guardian DF light with strap-mount base also attaches nicely and securely to the waist strap attachment points at one end of the SE and is readily available when needed. I have not checked to see it the light will fit with the waist strap attached as I use the SE with the wrist strap.
I find the light useful and also like "its look", esp. on the Swift.
Note - the jute bow tied around one of the Swift carry handles quickly demarcates for me the location of the specific O-ring where my keys are attached. I like its "look", too!
Hope these suggestions are useful to others, as many of yours have been so useful to me!