Using other peripherals with a TFT LCD screen controller shield

Hey devs!

I'm using a touch screen controller shield on a Mega attached to a 3.2" touch screen to build a control panel.
I would like to control some relays and receive data with an NRF24L01 from other modules around my house, but I'm realizing now that the controller shield uses all of the digital pins I would normally use to control other peripherals like the relays and say a temp/humidity sensor.

What is my best option here?

I was thinking using the SDA/SLC or one of the other 3 TX/RX pairs to communicate with another Arduino, say a nano, whose digital pins I could use to control other modules?

Thanks!

Sorry, thought I posted this the first time

As you can see, PWM pins 8-13 are available plus AREF (not sure what this does) and GND
Coms 1-3 and SDA/SLC are available,
And finally, all analog in pins are available.

Based on my understanding of the Relay module, there isn't a way to change it to a (+) trigger.
This is why I normally use the digital pins (digitalWrite(pin, LOW)) will send ground to that pin.

The COMMUNICATION, PWM and analog pins can be used as digital pins as well.

Also check the screen data sheet, which pins are really used for signals, not only stick to the shield for mechanical stability. Your picture suggests to me that most pins on the two-row connector are still available.