In fact, this sketch I wrote uses all 4 boards:

https://github.com/ShortCircuitsUK/CodeExamples/blob/main/Devices/Sensor_Graph_Alarm_Clock.ino

It doesn’t use the SD card, but it only uses 13 out of 18 pins. So it should be easy enough to add the SD card code to it.

Here is a connection diagram that should support all functionality. The switches are connected to the pins that serve the RTC, so as long as you aren’t pressing the buttons when the RTC is being accessed, it should work…