How to manage Redwood using different Workflow / Approval process than old pages?

Some of the Redwood Pages use different Workflow / Approval Processes.

For example: Updating an employee's location or department uses "Manage Employment" process in Person Management (Classic / Responsive UI), but it uses a different process called "Change Assignment" if a location or department change is submitted from the Redwood page.

In our environments we have quite large and detailed approval rule code written. I imagine there is a simple way to do this, and I am looking for advice, suggestions, or best practices.

I imagine many other customers that have developed large amounts of code for workflow / approval rules have found an optimal way to manage these with the new pages and new transactions.