I have read they can pinpoint the paper grade and exposure time, so no need for test strips.
Forget it. An enlarging meter can provide a pretty good, but preliminary estimate of grade and exp time, and thus your one and only test strip will be finely spaced around the correct value; But nothing replaces a visual appraisal of the test strip, dried, under proper lighting. Sometimes even, after a full print you realize some changes are in order.
And yes, a densitometer is a valuable tool for process control.