I ordered several boards in the 1.0 release in the fall as replacements for 0.5 boards that are currently in the field. Our setup for those involved using DIN rails to connect large marine cycle batteries so we could keep our terrestrial stations operational during the winter. So, we used the 12v regulator on the 0.5 board and it has worked really well.
For the 1.0 boards, I wonder if we could order a bare wire version of the step down module you linked, and then just connect that to a JST connector for where the solar panel input is. Can you think of any issues that may arise with that type of setup?