It seems like it's just counting the number of parameters passed into EXPORT? "index.html" is the resulting exported file but it's counted as if it's a cart.

Hi.

The multi-cart export command I've tried and understand is
EXPORT output_name.format [option_cart.p8 ...]

and the currently loaded p8 file is included.

If the PICOWORS.p8 is loaded when you EXPORT, then the above command, the

PICOWORS.p8
PICOWORS.p8
ENGINE.p8
CREDIT.p8

are the four exported carts.

I was similarly confused.
I think the confusion issue is that you don't get any warnings when the same cart is included.

Oh weird. So I didn't need to specify the current cart. I guess that makes sense. Thank you!