Do modifications made to configurableCaptureDeviceForPrimaryCamera while an ARSession is running change the output of captureHighResolutionFrame? What about modifications before running a new ARConfiguration?
No, any modifications to ARConfiguration object does not affect a running session. You need to call run(_:options:) after modifying configuration for it to be used.
You can change capture device settings such as exposure, white balance etc, that will be reflected in the output of ARSession. However, you cannot change the input/output configurations on capture session.