To our knowledge the LCD should work along with JTAG debugging, the EN pin is only shared so the screen is reset along with the MCU.

The MicroSD will definitely interfere if it is initialised in the software, as it uses all of the JTAG Pins (12,13,14,15), however the camera does not appear to interfere.  The ESP32-CAM works with JTAG and has the camera module built onto the board for a very low cost as an alternative.

As long as you don't initialise the pins in software, or use the MicroSD Library, or connect a device to those pins (e.g. insert a microSD Card) then they should function as expected with the JTAG debugging.

You can also check for the VM_DEBUG_GDB define in your sketch, so that code is active or inactive when using the Hardware Debugging:

	#ifdef VM_DEBUG_GDB
	Serial.println("In GDB Mode");
	#endif 

Just to make sure I understand correctly - if im not using the board to debug another board - as in im debugging and running my sketch on this board I should be able to use the JTag pins too (unless I wanted to use microSD - which I 100% dont)
thanks

If you want to use the Hardware debugging, you cannot use the JTAG pins in your sketch, and the jumpers have to be present on the board to connect the TMS/TDO/TDI/TCK to the onboard FT2232HL Chip (as shown on this page, in the JP2 Enable Hardware Debug row of the table).

The NC/XTAL pins are for the external oscillator which provides the clock for the ESP32 (detailed here), which can be seen in the connection diagram on the top right segment for the ESP32 Module on this page.