Cueing that trends outward is not an indication that A/S is set too high.
1. A/S on many arms (including yours) is engaged at all times. When A/S is engaged it provides an outward bias.
2. Absent a source of resistance, if the arm is free to float L or R, an outward bias will cause it to move outward.
3. Once the stylus locks into a groove the sidewall/stylus interface provides lateral resistance, so now the arm stays put (over the groove).
4. Further, if the LP is spinning then the skating force we're trying to counteract comes into effect. This provides an inward bias at the stylus which the A/S mechanism's outward bias at the armtube is *meant to* counteract.
Dan's suggestion to increase friction between the armtube and cueing support in some fashion may provide enough resistance to allow the arm to cue more staight down. As to how to adjust A/S on this arm, hopefully someone with first-hand knowledge will chime in.