Epson Digital Ice and Cropping

For the Epson V500 Scanner and similar, the instructions say to set
cropping at Small if Digital Ice is checked. Is that because Large, in
putting a black border around the whole image confuses Digital Ice?
I'd like to use Medium or Large crop setting to get closer or
completely to a full frame image. If you have encountered this, too,
your experience and advice is appreciated. I find that the combination
of Digital Ice and Unsharp Mask gives a nice result -- clean and
sharp, with only occasional cloning (Stamp tool) is needed in
PhotoShop.

Is there something with the Trimming On/Off setting or anything in the
Epson Scan Destination area that is related to how cropping is done?
Epson's Guide and Help are confusing, seeming to sometimes use "trim"
and "crop" interchangeably.

Thanks,
Neil