I’m not certain about how this GPIO Assist works...
I’ve always wired/connected directly to the RPi GPIO
(I’ve never found the need to buy these type of boards, but I can see how they can benefit novices)
However....
The main SPI connections for all these LCD will be the same (as the RPi only has certain SPI GPIO)...
But...
The 3.5” LCD will be using a 5V connection for powering the Back Light (LED) and LCD (out of the box)...
You may be able to move this to a 3.3V GPIO (I’ve always just wired the 3.5” LCD to 5V)
But
I always tend to remove the black block which is on the LCD board used for quick and solderless GPIO connections...
(it’s easily removed and lowers the profile of the LCD board)
This will then allow you technically to wire the LCD how you see fit...
But the SPI connections going to the RPi GPIO are pretty ridged/specific, so you only really have flexibility with the GND and maybe the 5V...
.