Suggestion noted.
We have no plans right now for adding this. If there is time we'll try and do it in our next big release in about 6 months.
Until then perhaps you can revise your listings on eBay after listing to add the needed info. A bit of a pain but a potential work around.
You can also use our Get HTML feature to still create your listings on our site and post them on eBays sell your item form.