Yes, the download is limited without quantity. Luckily, the file structure to generate the spreadsheet is very simple. Looking here:
PHP Code:
'v_customers_country'    => $iii++, 
'v_customers_telephone'    => $iii++, 
'v_customers_email_address'    => $iii++, 
'v_products_model'    => $iii++, 
'v_products_quantity'    => $iii++,
'v_products_name'    => $iii++, 
'v_products_options'    => $iii++, 
'v_products_options_values'    => $iii++, 
you can see I added the quantity after the model number.
Then it should be added again like this:
PHP Code:
date_purchased as v_date_purchased,
orders_status_name as v_orders_status_name,
products_model as v_products_model,
products_quantity as v_products_quantity,
products_name as v_products_name,
products_options as v_products_options
It needs to be repeated for each type of output you want. I did it for the first selection.

I'm going to look into other ways to manipulate the output like dropping the extra data and adding a line between orders.