I’ve recently been working on a headless Pi project using the GFX Hat and a Pi A+ and I am now exploring battery solutions, I’ve found battery solution that uses a Pi Juice Hat, which allows for all GPIO pins to be accessed, however on Pinout.xyz both the GFX Hat and Pi Juice Hat both use GPIO Pins BCM 2 and 3, will this prevent the GFX hat from working as intended?
BCM 2 - SDA and BCM 3 - SCL are i2c, which is a shared bus. If both Hats are using those pins as i2c and they each have a unique i2c address, they should be fine. No two devices using i2c can have the same i2c address.