I'm currently working on a new detector board that makes this whole thing more modular and usable. It is going to include variable SiPM bias voltage and preamp gain this time. There will also be a better option for mounting than just the pin header now. And last but not least, I'll change the preamp and SiPM DC/DC converter to fit better parts!
In the mean time there is a new SiPM carrier board design! It's way smaller with 18 x 18 mm and also less stupid with the holes in the PCB, because there are no more holes (well, except for two tiny vias) that could make it harder to isolate the sensor from light. Enjoy!