You can snip off the A4 pin from your display shield. Your I2C bus will work ok now..
My library should reset the controller in software. So you do not need the LCD_RST pin at all for your ST7789V, ILI9341, ILI9488, ...
Note that users with the older style controllers like ST7781, ILI9325, ... do need the LCD_RST pin. They should not snip off their LCD_RST pin.
David.