I recommend adding some glue on the sides of bottom snap covers to keep the lid attached better to the main case. In this case I tried to align the SD card accurate as possible.
Manually switch goes on top, BMS goes to side where C-Type hole is, glue it ON BOARD, NOT CASE as close to hole for whole raspberry pi zero and display removable. Connect battery and move battery in the back where back cover is and add foam at the brackets to secure the board or press to case, and battery, so it won't move along the case.