If it is a big marketplace for you, it may be worth speaking to eBusiness as they have made a lot of 3rd party integrations for Linnworks. Alternatively Linnworks does have a customisation team too :)
All the best,
Fitted Commerce - Ecommerce Agency and Linnworks Specialists
The Linnworks User Hub - Facebook Group for Linnworks Users
I sell on bonanza.com. I want to integrate with linnworks but there is no integration. Please can you add that.