Is your feature request related to a problem? Please describe.
We use Lamar as our DI container https://github.com/JasperFx/lamar which has an Auto Wiring feature - https://jasperfx.github.io/lamar/guide/ioc/auto-wiring.html#auto-wiring

ReadFrom.Services is looking for a concrete LoggingLevelSwitch which means Lamar will provide an auto wired instance even if I don't register one. That means that if I use ReadFrom.Configration (in the recommended order before ReadFrom.Services) my minimum level in appsettings isn't respected.

Describe the solution you'd like
Add an interface to LoggingLevelSwitch and look for a that interface in the service collection - this is in alignment with the other configuration points that are resolved from services.