RLV News links us to a news post by Lunar Lander Challenger SpeedUp. The application for experimental permit has been given the go-ahead for review by the FAA AST, meaning that in a preliminary review there was enough material available for them to do the full review. Here's the FAA letter.
The previous day, SpeedUp had another post on their first rocket engine test firing with certain direct measurements. This post with all of the details about the test and what they learned is right below the one on the permit application. This post comes with the video Throttle Mapping and Thrust Vectoring.