I believe ZOHO is very smart software. But in reporting side, all the reports are such way that, zoho wants to promote ZOHO Analytics and hence don't provide proper reports. This is really unfair. I don't believe that such a smart software can not provide proper reports.
You must upgrade for reporting because reporting is the only key to manage and understand business.
In ZOHO Inventory, I have asked many many times for Category wise report but I am still waiting.