The things we take along when it's not all about the time on the clock? I started out with everything as minimal as possible but now enjoying a mix of low pack weight and comfortable stops, making the most of the time at camp as part of the ride as well as travelling light and as far as I can.
My #1 has been something to read. I've enjoyed picking up random books from phoneboxes or bus stop libraries before, or taking one of the Penguin series of small books that I pick up whenever I see them (gotta stay lightweight after all, and some of those little books are heavy on thinking needed

Mini speaker, check - my OS Buckshot's been great on rides in the past. Really enjoyed the wide open roads of France with some good music on.
Camp lighting - generally use a headtorch but recent trips I've had a back up USB LED front and rear and used the front for lighting the general area, if I'm somewhere very rural and not bothered about keeping a lower profile.
Folding foam sit pads are a must-have too. They double up as insulators for a packable rucsack, to keep the heat of the sun and/or your back off the food or cool beer (wrapped in a down jacket oc). I've wondered about cutting up a foam mat to make a sit and back rest but the material's bulky.
TBH my greatest luxury for a bivi spot is a view of the sunset, I've spent a few evenings just watching the colours in the sky change over a slow dinner. Lightweight and free.