World aligned texture in unreal is probably one of the most over complexified methods of triplanar mapping that I have messed around with, if you need simple planar/triplanar mapping, you can copy one of the incredibly simple material function in the image attachments, it will cost way less, and doesnt include a lot of stuff that really isnt useful. My solution wont work extremely well on smooth, round objects but on a path, a block, rugged, uneven terrain, etc, it will work perfectly. For the path in the image you gave, simple planar mapping will work perfectly fine. If you need high quality smooth transitions between sides, try stripping down World Aligned Texture node already put into ue4.