No payment apps except for directpay trigger preordervalidations. Litium is working on adding support for this.
Why it is working for direct pay is because directpay calls checkout api to place order and that triggers validation. The other apps create the orders via connect api that doesn’t support validation at the moment.
The ability for the Connect Payments API to trigger order validation before order is placed will be added in Litium 8.8, planned for release 31 January.
The ability to call Litium for order validation then also need to be added to the Svea app. That has not yet been planned, but we are of course aiming to add it to the app soon after the 8.8 release.
The ValidateCartAddressArgs is used in the AddressChanged callback in the Connect Payments API. The Klarna app implements this callback in the Address Changed callback that Klarna Checkout triggers each time the buyer address is changed in the iframe. Svea however does not have this callback in their checkout solution.