The transfert of NNID of your 3ds xl emunand 9.4 --> 2ds sysnand 9.4 must work.
if you backup your emunand 9.4, and all the data of the sd of the 3ds xl, make the transfert, and restore all the file of the SD and restore the emunand, you should be abble to play of the game of the two console, but never try to go to eshop (games may be deleted).
This is good to know, but somehow I messed up in the process of creating the 9.4 EmuNAND. I followed the MaxConsole guide note for note. My SysNAND is 9.2 and my EmuNAND is 9.4, so that's all good, but after restoring the contents of my "Nintendo 3DS" folder (which had all my downloaded games and saves), the games don't show up on my Sys or EmuNAND. The folder with the long string on the formatted EmuNAND card is different than the one that I backed up before formatting. I assume I will need to inject the NAND.BIN I made of my 9.2 3DS XL into the EmuNAND SD card using the EmuNAND tool?