Make balance adjustment into a record on the account
When adjusting account balance (most often used on the cash account) the current functionality simply adjust the "starting amount" value on the acount. This completely destroys the historical data about the account.
Instead the balance adjustment should, by defaul, add a new entry in the account that records exactly enough expenses or income for the account to reach the new adjusted balance on the date/time when it is indicated. So that this adjustment then also shows up in all reports as an unknown expense/income and you know that - yes, I spent 10$ that month from cash, even if I don't remember on what exactly.
Ideally it should be saved as the specified balance value and not just converted to a transaction, so that if I today write down that "right now there is 25$ in my wallet", I can still go back later and write down "oh, right I left a 7$ tip in the restoraunt last weekend" and this new expense entry would not ruin the corrected balance of my account.