in a nutshell you can’t do this, I’m now forced to run a uk site and shop under a co uk domain and a .com for the euro market as shopify markets is incapable of separating inventory by customer local. So all you stock from all locations is available to all customers irrespective of location.
even the new updates where shopify is pushing markets, again they have completely missed inventory management by location.
they really are not thinking international but cross border shipping, it’s a different thing.