Dear Zoho CRM team , 

The integration between CRM and Books ( Finance ) is  essensial and is important part to make Zoho into ERP. 

But the way of current integration has many weakness. After integration , invoices / salesorder,... are controlled by Zoho Books, there are few problems : 

- There are some blur area , whereas the access and permission are not clearly identified ( like selling price / rate permission to edit is not the same in Books and CRM ) 

- And many important functions in CRM for invoices / salesorder such as workflow and custom functions, blueprint will not be supported.

And we use invoices/ salesorder as module in CRM , there will be no integration to Zoho Books ? They are independent module

Hope my observation is correct. If so, it will limit much power of advanced function of CRM now and more in future. 

Thderefore, could you consider the following Integration methods : 

1 / Integration between module in Books and Modules in CRM. invoices in CRM with invoices in Books , Sales Order in CRM  and Sales Oder in Books ... maybe estimate stay in Zoho CRM. And their is link to open. Maybe , Zoho  did not choose this as it need may sync and many errors ?

2/ Use Native Estimate Module in CRM, if sales is successful, then options to convert it into Invoices or salesorder. Then SalesOrder & Invoices are Books Native Module. 

Estimate will show converted. Once paid / void / .... in Books , it will sync back to Estimates. 

Hence , Estimate will act as Estimate / Invoices / Salesorder in CRM in Integration scenerio.

And so we can have advanced functions of CRM on estimate ( invoices / salesorder) 

In this option , it is smooth flow between sales team accountant . Sales stop at the end of Estimate and Accountant will take control from there . 

This is my 5 cents thought .