I had my first go - by mistake - in a UL RG today.
I'm not so concerned about the slope of the lie (in real life), just where the ball is in relation to my feet. Rather than dots, it should be like an elevation. More below your feet, more right. Above, more left.
But what totally threw me was uphill lies. I had a 135 yard shot with a tail wind and nn uphill fairway lie. Nailed an 8i (145y) and it went...............103 yards. I can say after 30 years of playing A grade golf that I've NEVER seen anything close to a fairway lie that'd do that!