It would certainly be possible to add another report for ‘Total sales by Product by Customer Type’, but the only issue is that there are myriad combinations of reports that different customers might want. We must be careful not to make the reporting section too difficult to navigate by adding many different reports. The best solution would be to add greater functionality for reporting building. We have looked at this in the past and we would love to implement something, but it’s a sizeable task and some options would cost us a certain fee per report ran - so there are a few things for us to think about!
Anyway, in this specific instance, a potential solution would be to add the option to group by customer type in the Total sales by product report, but if you could post a feature request for a Total sales by Product by Customer Type report, we can discuss options there and gauge an idea of how many other customers would benefit from a prebuilt report like this.