What should happen to MFA flows when SMTP or OIDC provider are removed

The scenario:
- Admin configures an MFA flow with email and/or OIDC factor
- Admin assigns the flow to location(s)
- Admin removes SMTP configuration/OIDC provider

Questions:
- How should the MFA flow editor communicate method unavailability in the already-created flow stepsview?
- How should the system perform MFA flow during user connection? Different scenarios when the method is the only one available for the step vs one of many? What if this is the only factor in a single-step flow?
- Omit the step/method? Then perhaps it should also be indicated in the UI that the step is inactive because of missing configuration?