This[0] is the ESP32 module that I keep on hand. The seller doesn't list any information that would help with your simulations, but the photos can give you a rough idea of the physical size. Other than a bare ESP32 module[1] I don't think I've seen a physically smaller ESP32 board.

You can program these with the Arduino IDE, so they're quite easy to use and there are tons of libraries available for interfacing with sensors, etc.

[0] https://www.aliexpress.com/item/32834982479.html

[1] https://www.aliexpress.com/item/1005001271041790.html

Looks like the pocketbeagle has two 'programmable real-time units' PRUs @200MHz which could be used to run the sensors while the main CPU handles video+I/O. Could be a good option for 'multithreading' without having to insert another module. (caution: I've kept to the rpi for weird little side projects, so haven't actually tried this. Double super big caution: Never add hardware before profiling your current system to figure out where the bottleneck is... it might just be a matter of changing your 'main loop' a bit.)

http://beagleboard.org/pru