You know how in ORAS if you talk to Lanette she will ask if you want to change ot order of commands in the PC (specifically, moving "Organize Boxes" to the top)? How do you do that in XY?
I've talked to Cassius but all he wants to do is tell me what the PC is, and I'm getting annoyed at constantly accidentally hitting A and going into "Deposit Pokemon".
You can't change it in XY; this was a feature introduced in ORAS by talking to Lanette. If it was available in XY, Cassius would be the logical person to initiate it, and he only ever explains the PC storage system to you when you talk to him.