In modeling the road or site with geometry corner in 90 degrees or sharp, the small arc of corner is required in order to model the round corner. So that no overlap between 3d linear geometry. Software should provide the option to allow the corner become 90 degrees even in the corridor modeling.
It is required while running the retaining wall in the site models.
I too use linear templates to round corners at PIs, but it is not working consistently. I have several that in a single run of a linear template, most but not all inside corners process correctly, but I get a few, usually larger inside corners (90° turns, etc.) that will form a "bowtie".
Linear Templates will model around a corner. I use linear templates for all my retaining wall models. If end conditions are required I would recommend using components to target terrains etc... Components inside linear templates "heal themselves well" or target to themselves where end conditions seem to have trouble with this.
Zane