While it is easy to create ATR's with APE, is there some way to create and/or change the titles of an ATR using just the SIO2SD? I'm not aware of any way to do this.
I've looked at this for my own situation, and it looks like the easiest way to create the ATRs would be to use makeATR (PC utility) each time you wanted to create and then copy to that ATR. Or you can copy a "blank" ATR of the correct size to the card and then change the filename. But once the ATR is named and placed on the SD card, there doesn't seem any way to change the ATR filename except to take the card out and insert it into a card reader. Definitely doable, but seems quite a bit more cumbersome than using APE.
One frequently reads the objection to APE (etc.) that "I don't want to be tethered to a PC," but some how, some way, the PC seems still needed with any of the imaging systems.