Thanks for contacting us. Looking at your case I would think that the L1S array would still be your best bet unless you wanted to be able to adjust the height of the wall or some other attributes.
Another option can be to use multiple L1S arrays to achieve your desired effect. This gives you a lot more flexibility and for styles like this, it can often be easier than trying to make it work with the A2S array.
If you want to learn more about the A2S array there's a useful chapter in the getting started with RailClone guide here: https://docs.itoosoft.com/railclone/getting-started-with-railclone/9-create-your-first-2d-array
If you'd like more specific help with this case, if you could upload a basic scene file and let me know what parameters you'd like to be able to adjust, I can give you more focused advice.
Finally, the pinching issue might be resolved by increasing the Curve Steps value in the Style rollout. This smooths the spline and can ease deformation.
I hope that helps, please let me know if you have any further questions.
All the best,