These posts highlight some features of cs-cart multivendor
This post highlights some of the good and bad Complaints about CS-Cart
This thread highlights a problem with multivendor promotions, depending on configuraiton vendors either can’t create promotions or the promotions apply to all vendors not just the vendor who created it (this is an example of ‘working as designed’ where that is not acceptable) Promotions/coupons Do Not Work In Multi-Vendor