Regression testing, how to mock the API locally

Hi all, I am working on a website using to do passwordless authentication and want to set up some isolated regression testing of the UI using Playwrite and WebAuthn Virtual Authentication. I have my test working, but just 2 small tests create a ton of users because they are testing across many browsers.

What I would like to do is have an isolated local test system for full regression testing of my frontend, backend, and mocked vendor services.
For passwordless testing I want control over the UserDB to save the state for tests etc… and have it fully isolated from the hosted applications I have.

I how can I mock or host the passwordless server in my environment on the development plan? From reading the passwordless-server repo’s self-hosted it looks as simple as running the container in there. I Tried Using wiremock to mock the API calls but it causes all sorts of trouble when the website expects a valid token during login.

My other concern is cost. I am not in a position yet to use the passworldess enterprise plan (just the development plan) and it seems self-hosted is only allowed in the enterprise plan. Can I use the self-hosted solution on the development plan just for testing?

Is there a better way to set up this kind of testing? Does anyone have any suggestions or experiences that may be helpful before I start trying to use the passwordless-server self-hosted solution?