Hi lpinto,
I'm happy to shed light on the billable hours on transactions.
The billable hours are broken down to service dates and service details to make them transparent to your customers. At the moment, we're unable to group them into a single line item.
I'll submit feedback on your behalf. That way, our engineers will be aware that you like this option on your transactions.
If there are other things that you'd like to see in your transaction forms, please don't hesitate to share them with us.