Hello,
That's not related to the cron but only related to the plugin.
You can either try to duplicate the plugin to have other instances (and other settings) or perform a bigger modification to use the HikaShop multiple-instance system.
In both case, some custom development would be required.
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.