Well first of all I do not recommend using that plugin for multiple reasons. Secondly , this is a customized shipment quotation tool that needs to be embedded and would function based on user input . From what I have read , there are only a few more things that needs answering so that I can understand your deployment. So let me elaborate on that . Can you please tell me what type of API you will be using for Data set ( IF ANY ) , Can you tell me the type of Server you have ? and of course what type of CRON it supports?
Once I have these information, I will be able to build more wisely for you.
Thanks and Regards