Prior to v3.0, with the atumn and sun [[domains]] blocked, the system could be used with online services on non-latest system-versions fine. As of roughly the day following the release of v3.0 however, the system being on >=v3.0 is now enforced via an account-related [[Domains|domain]]. This affects everything using Nintendo-accounts, regardless of whether the current user has one linked or not.
This also affects launching the WifiWebAuthApplet on pre-v3.0. Error 2110-3400 is thrown while eShop is loading, with the conntest domain setup to trigger the web-applet(originally launching eShop could be used for triggering the WifiWebAuthApplet). This same error is thrown when attempting to connect to wifi from System Settings, on retry it will display a separate sysupdate-required message(different from the error message). With the dauth [[Domains|domain]] blocked, eShop has the same failure, however System Settings will launch the web-applet after it displays the "Registration required" message when connecting to wifi.