Thanks Ryan for the information.
We are potentially working with a various FIs that have asked for a similar modal interrupt prompt after login. We will share your suggestion with them, but if they still really want a modal interrupt page after login, is there a way to do it?
Our recommendation to acomplish this would be to build a widget for the landing page (https://docs.q2developer.com/guides/frontend_development/widgets.html) and use its execution to launch a modal (https://cdn1.onlineaccess1.com/cdn/base/tecton/v1.9.8/Documentation/index.html#/capabilities/showModal) or overpanel with the tecton javascript.
There would be no UI to the widget itself, just Javascript to launch the modal or overpanel.