Hi.,
I will code a extension to suit your requirements. When it is installed, merchant or admin can map it to the respected etsy shop for synchronization. You can add as many account as you want.
I am an experienced PHP, Magento, OpenCart & Wordpress Developer and been using [login to view URL] since 2009. So far completed 39 projects in freelancer.com. I completed all my projects within the budget, on time with 100% completion rate and with a five star feedback. This shows my dedication towards not just only placing my bid, but to complete the committed project with the time and budget.
Please check my full profile here: https://www.freelancer.com/u/x5to10pm.html and please feel free to message me for any query.
Thank You.,
Viswa