Hey blurflame, thanks for rising up the question. We are on the same page with you in our store.
Back then we were using multistore plugin and multisites tend not to work properly so far, also a license hassle.
So instead of writing whole thing from the ground up I found the ATUM plugin to fit the needs of the store.
Basically, we also need to preselect a city by one time ask and pick the inventory accordingly afterwards.
Users need automation and manual repicking isn't helping here, otherwise we would stick to multistore.
AndreaRebel hopefully you'll release an update soon, we are planning to go live with new version this month.
