Hello,
We started to work on a refactoring of the import system but due to the complexity of the ACL restrictions, it made the import difficult to use for vendors (unless you have specific configurations and give a big access to the vendors).
So, because the import should be really easy and friendly for vendors, what we do have is not suitable enough for a release.
Regarding the HikaShop backend import, yes, you need to provide the vendor ID so the link with the vendor will be made.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.