Hello,
It would require a custom development in order to create the vendor creation/update triggers and create a Joomla menu accordingly.
Since HikaMarket have a "vendor listing" menu to handle marketplace with a important number of vendors, having menus created for vendors did not feel interesting.
Depending your organisation, you might want to classify the vendors in sub-groups, to avoid lots of entries in menus. And if you have few vendors, you won't manage your marketplace automatically (manual creation of the vendor, or at least the confirmation).
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.