Thank you for reaching out to the Community, @Pickle.
Let me provide you with some insight into allocating classes through rules for inventory from Zoho in QuickBooks Online.
In bank transactions, it is possible to add rules for classification for a specific class. So, if the inventory is included in the transactions that come from Zoho you can create rules so QuickBooks will categorize it to the correct classes. However, for individual inventory, you have to manually allocate it once added.
To make sure they end up in the right accounts, creating bank rules can speed up the review process by automatically categorizing your transactions for you. Over time, it can even scan transactions and add details like payees.
I've also added this article to connect your bank or download your transactions, QuickBooks looks for and tries to match them with existing transactions. Also, by tracking transactions by class, you can easily monitor each segment, run reports to analyse sales, costs, and profitability, and use this information to plan ahead and set budgets for each class:
Feel free to post if you have other concerns with rules or classes in QuickBooks. We're here to help you further. Keep safe!