It's possible to add budgets for accounts, and from the account you can divide the budget among your kostnadsställen. You can also add the budget for an account as unspecified, instead of adding it for a kostnadsställe. When you add the budget as unspecified, you will not see the budget if you look at a report for a specific project.
If we want to start using this, we might want to review our kontoplan to closer reflect our budget. This would probably mean reducing the number of accounts. We would need to check what accounts we need for good bookkeeping practice, transparency towards our members (for exemple, for the budget it would be good to have all travels as one account and not separate it into trains, air planes and so on, but if a member wants to see how much we spend on flying compared to trains it's good to have them separeted), and possibly other reasons (some accounts have to do with different kinds of VAT).