I think one of the reasons you haven't had a response is the worry that by allowing you to shadow them they would be breaching GDPR! You would not be an employee & we have to keep our client's information confidential!!
I suggest you go to your local branch meeting & ask if anyone can help you by showing you how they use their technology.
Auto Entry is good as it stores invoices (supplier & sales) & a copy is uploaded to whatever accounts program you use, so you don't need to keep the original invoices.