In StarSteer you can work in VS scale and change VS azimuth at any time. Well trajectory and interpretation will be projected to the selected azimuth. VS Azimuth change won't affect your geosteering interpretation.
We don't limit our customers and if they prefer MD scale - they can do the interpretation in MD! They can switch to VS and back at any time! It doesn't affect your interpretation at all.
You can do the geosteering interpretation in 2 domains now: VS (at selected azimuth) and MD.