@InfoHunter, let me try to explain again. I’ve already linked you to the relevant Guides, except for one that became relevant only after your most recent post. (You have dribbled out your needs only a little at a time.)
In Manager, customers are actually subsidiary ledgers (or subaccounts, if you will) under the control account Accounts receivable. So they have balances. Transactions in those subsidiary ledgers can be reported with Customer Statements. If necessary and desirable, you can modify the control account under which a customer is accounted for to a custom control account.
The easiest way to track advances deposits by customers is simply to credit them to Accounts receivable and the customer’s subaccount. That is explained by this Guide: https://www.manager.io/guides/7093. This Guide is now linked because of your recent statement that you were looking for the simplest approach. The disadvantage of this simple approach is that credit balances in the subaccount will automatically be applied to unpaid sales invoices in the order of oldest due date first. If there is a lot of activity for a customer, you can lose visibility.
Special accounts come into play when you want more visibility. But special accounts are not, as you seem to think, the same as control accounts. Instead, they are a way to consolidate your balance sheet. They are custom subsidiary ledgers; accordingly, they are assigned to a control account of their own. They can sometimes be parallel to or mirror customers’ subsidiary ledgers, but do not replace them. The example in the Guide you referenced shows how individual real property trust accounts can be lumped together for balance sheet purposes while still tracking monies related to individual properties.
I recommended special accounts when the only thing you had indicated you were interested in was some kind of internal prepaid fake money. When special accounts are used in this way, they can be thought of as a liability, money you hold on behalf of a customer and ultimately owe to that customer. Thus, they can be used as a source of funds for settling obligations from sales invoices. The example in the Guide about gift cards is similar to what you want to do. But you do not use a special account in place of a customer’s subsidiary ledger. Nor do you use it in place of a control account, whether the default Accounts receivable or a custom control account.
Based on what you have shared so far, you have no need for a custom report. Nor do I see any need for custom control accounts. You really don’t need special accounts. You just need to record deposits/advances by your customers to their regular subsidiary ledgers in Accounts receivable. I suggest you try several experimental transactions that way in a test business. Look at the reports you can generate and decide if they fit your needs.
If you decide you need more control, only then set up special accounts. The thing about going that direction is that you will gain no additional built-in reports associated with the special accounts. You will just have more concrete visibility into the liability you are carrying on your balance sheet by virtue of holding all these deposits from your customers. (That, by the way, is something you may have difficulty convincing your customers to do—pay you money against the possibility of future work.)
Understand in using special accounts that they are designed to benefit you, not the customer. They are meant to give you more visibility into what is on your balance sheet, not generate additional reports for the customer. You won’t need to, because the Customer Statement will tell the customer what they need to know. And it is not your job to educate your customers about what a statement is for. You are not (presumably) running an accounting education consultancy.
Many users become enamored of arcane features in Manager. Most can actually get by with very simple, built-in and default capabilities. Talk with an accountant and determine the minimum setup you need for your business operations. Implement only that.