I am building something like this, but the pandemic has prevented me from collaborating with my frame maker. The e-ink panel I have has a fairly fragile ribbon

I am building something like this, but the pandemic has prevented me from collaborating with my frame maker. The e-ink panel I have has a fairly fragile ribbon cable we are trying to hide inside the frame with some clever cuts. I am not sure how the panels for Kindles allow them to have such small margins. The biggest problem I have is fitting a battery into the frame -- I was trying to find a low profile USB battery pack that could output 5V for RPi Zero. Maybe I should wire up some battery cells directly to evenly distribute the weight?