Panasonic PGS could be use to transfer the heat from the FPGA to the Camera Body. It can reduce weight and makes the Camera smaller in the ideal case the Apertus doesn’t need a fan. More Information: Video:

A hole can be cut in the PCB to allow a metal plate to touch the back of the sensor kac-sensor-socket-board.jpeg (image courtesy of danieel)

Practical experience of cooling down a d450 sensor to sub-zero temperatures with Peltier

danieel, [1]:

uncooled sensor without any thermal management gets to at most 45deg (internal reading).. so you should rather cool/separate the fpga, than care about a sensor (big package with relatively low power)